Only ever in one car. 1969 VW Van, with a semi-camper interior (bed, fridge, etc). It was awesome. Roll out of a bar hammered, chick in tow, and just hop into the van and get at it. Sleep until sober, then drive home. Her too, if she was still there. Had it for 3 years, while DJ'ing at a night club, and playing rugby. The only reason I got rid of it was because the frame snapped. And no, that wasn't a reflection of the women I was "dating". For the most part.
I lost my virginity in the front seat of my 1980 Impala. That thing was so huge we didn't have to hop in the back seat. I kept it classy, however, by parking behind a grocery store. For awhile, breaking in a new girlfriend meant having sex in my Saturn. By way of comparison, Saturn SLs are nowhere near as comfortable as the Impala was, and if you have a stick it can definitely hinder things. Somehow I made due though.
Let's see: My second time was in my first car, a 747-sized 1983 Chevy Caprice Classic. Manute Bol could lie down in the back of that behemoth. At the Drive-In, in my 1995 Olds Achieva (don't ever do this, unless you're a pure exhibitionist. The windows instantly fog and EVVVVVERYBODY in the drive-in knows your knocking boots). In a church parking lot in my 2000 Sunfire (not a comfy shaggin' wagon). Most memorably, in a Limo, under a blanket on the way from Grand Bend with 6 others in the car.
I have only done it in Honda Accords. I had a 1991, and my girlfriend had a 2004. To be honest, the 1991 was better. I am 6'3 and it was a bit wider so my legs weren't sticking out the window. also the front seats moved forward more in the 1991, so there was more room to maneuver.
I lost my virginity in the back seat of an olive green Ford Granada (don't remember what year the car was - had to be late 70's though) with vinyl seats and let me tell you - it SUCKED! We were in an elementary school parking lot on Halloween and the cops drove up, lights flashing. I practically had to pry myself off the back seat for I was stuck to it with all the sweat. I couldn't find my clothes until the last freaking second. The cops asked me if I was okay, told us we were on private property and let us go with a warning which was a good thing because his very religious dad would have killed him. The smallest was some sort of Datsun hatchback with the prick from my prom picture. We were in the passenger seat and there was another couple fucking in the driver's seat (better them than us). Off topic: something just occurred to me - while I've never swapped partners, I've fucked in close proximity to other couples fucking an inordinate number of times.
My current car, a Mazda 6. The last hookup in it happened about 3 years ago. Parked it on this insanely dark street that connected two nice neighborhoods. Cops never ever came there (I know because that's where I used to drive to smoke). The car is white, with black leather and, at the time, had really dark tinted windows--no one could see anything. It was perfect. The back seat was a little cramped, but nothing we couldn't handle.
Smallest car would probably be mine, the Civic. And apparently city parks close at 11... who knew? Also lacking space is the Chevrolet Cobalt. I have a bit of a weakness for boys who drive big trucks so there have been a couple encounters in the middle of a field and in a grocery store parking lot.
Back in high school my girlfriend and I would alternate using her '02 Malibu and my '96 Civic, but we always preferred the backseat of her car. Something about the position she would lay in made it easy for her to come so it was always easier to convince her we should take her car out. We used to bang in the parking lot of a local CVS but after the second time a cop knocked on the window and told us to move along we had to find somewhere more secretive... like the graveyard by her house. Fucked up? Sure, but it was quiet and no one would drive by it at night so it was perfect. I've hooked up in the passenger seat of a girl I used to work with's VW Cabrio too. It was during a really humid summer storm, which actually made the sex feel kind of epic, though maybe I was just delirious from sweating so much. It was cramped as hell, which was her fault more than VW's, it looked like she was living out of her car there was so much stuff in the backseat. This also occurred in the graveyard. If it aint broke, don't fix it right? I'm definitely going to hell.
First: Ford Escort was the first. I was 16 so it could have been a Smart Car and I still would have found a way to make it work. Worst: Dodge Ram 50... basically the smallest pickup truck ever made. The seat belt receivers stuck way up in the air and couldn't be moved. There was approximately 2ft from the dash to the seat, the length of the seat was maybe 3.5ft. Super fucking small truck that didn't have the benefits of a reclining seats like the Escort had. Best: Buick Roadmaster Wagon. This fucking thing was designed by engineers who were concerned about fucking in the back seat of the car. The back seat kind of wrapped around like a comfy restaurant booth and the padding on the seats rivaled the best pillow top mattress. It was down right comfortable. The vehicle I'd love to get laid in is my F-350. Huge fucking seats, plenty of ceiling height, lots of grab handles. Yeah I've gotta break that fucker in.
This here was my first car, a 1984 Pontiac Grand Prix Brougham: And here was the backseat: It's even comfier than it looks. I only owned it for 4 months before frying the transmission (Always check the level of tranny fluid when buying a used car. I learned this the hard way) but I got more than my fair share of action in that thing with my ex. And with a bench in the front seat too, we didn't even have to move to that back if we were lazy that night. I've since done it a few times in my Civic, but it just isn't the same. Way too cramped, the discomfort sometimes just isn't worth it.
As a high schooler, sneaking out, picking up my girlfriend, and taking her to a secluded parking lot or neighborhood was the norm on a weekend, or even a schoolnight for that matter. Since my family always had at least 4 cars readily available, i was able to pick and choose which ones i wanted to use (as long as they were parked outside of the garage). I've had sex in a Ford Taurus SHO (took said girlfriends virginity), a volvo, and the smallest/worst was a Dodge Dakota Sport that didn't have an extended cab. It was really cramped and there's no way my post-college body could pull off that feat. It was so cramped, in fact, that there were multiple occasions where while shifting positions a hand would accidentally lay on the horn, initiating a quick getaway.
The back of my Dodge Durango was far and away the best. Both the second and third row seats could fold all the way down, and you basically had twin sized bed. You could (and we did) practice a fucking kama sutra book back there. No limits. This was nice for waiting out the lines in the parking lot after football games, getting away for a quickie at a party, road trips, etc. 10/10. Recently I tore it up and the back seat of my buddies brand spanking new 2009 4Runner. Plenty of room to get the job done comfortably. I give this a 8/10. I came back into the bar with a smile on my face, and he immediately realized what happened. He was pissed that I christened it before he did. My F-150 isn't too bad, and provides you with a couple options. I brought a random out of a bar and knocked it out in the parking lot in the bed of the truck. The problem here is that you have to stay lower than than the rail of the bed. Also the bed of a pickup truck just isn't comfortable at all. I've got a spray on liner. Ouch. 6/10. It's an extended cab, so I've also brought a girl out of a bar and went at it in the backseat of the cab. This is crowded, and you're pretty much limited to missionary. Also causes more rocking than the bed, curiously enough. 6/10. In highschool my buddies dad owned a bunch of dealerships and he was always test driving different cars. One night I think he had a Hyundai or Honda, or something. It was really weird. It was almost like a hatchback, and when you opened the back hatch, seats would pop up. Anyway, one night he drove me over to our classmate Sara's house who had a smoking hot sister, who had a crush on me. I told Sara to go get her sister to come out, but her sister was already in bed or something. So I asked Sara to give me some head instead. So we got in this weird backseat/hatch thing and she went at it while we were about two feet behind my buddy in the driver seat. He snickered the whole time. Not really relevant to the focus, but I love this story, and always forget about it. So, uh, that weird car gets a 9/10 for head getting ability.
First: I, like wickedbitch, also lost my V card in the backseat of a car. It was my then GF's '94 or something grand am. Piece of shit. The sex obviously blew hard. Worst: In a city park in my single cab S-10 pickup. It was a manual too. She had to climb over the shifter and on to me. Then had the steering wheel jabbing into her back the whole time so she really couldn't move. After about 5 min of trying to find a decent position we see out of the foggy windows a car rolling up. Great. Po's decide to roll around the parks after dark to catch little shit's like us. Lo and behold, the car stops behind us, we hear it's door open and close, and then footsteps. She scrambles off of me and back into her seat when we hear a tap tap tap on my window. I roll it down and sure enough it's a Po. She has her pants about 75% of the way up her leg when I roll it down and he tells us the park is closed. Worst 2: Hooked up with a friend of a friend in my buddies car. It was a Vibe or something like that, so there as a decent backseat. I was wingman so he could bang the hot milf. He never did and all four of us had to drive an hour home in that car with it smelling like sex. Not too much fun.
The first time I had sex was in the back of a Toyota Caldina that was parked near a beach at about 2 in the morning. The second time was at about 9 am the next morning, I don't think anyone saw us.
I've gotten some road head in my Civic and my old Grand Am. The only car sex I have ever had though was in my ex's Honda CR-V. I thought it would go a lot more smoothly than it did, that being a decent sized car and her being a small girl. But we just didn't fit very well. Also, because we were parked in front of her recently deceased grandmother's house who had a several nosy neighbors, we decided to give up and go back to her parent's house and use her high school bedroom instead. All's well that ends well.
My first hookups were in a VW Beetle I drove my senior year of HS (screw you, some asshole totaled my Accord when it was parked in Milwaukee and my Dad got the Beetle in planning for my sister driving it in a few years.) Despite the size, the roof is comparably quite tall so that thing was a spacious bubble. Move up the front seats, climb in back, and you are in business. My ex-gf in college drove her Dad's Audi A8 for awhile. That thing was a MONSTER. We fucked in the front seat quite a few times when we couldn't go back to her place with her parents around. I drove and Expedition for my last 2 years of college, never hooked up in it, cause frankly, it was college and a bed is always better than a car.
I've only gotten head in a car. My 94 Celica. It was the same ghetto girl I mentioned in another thread who could suck start a Corvette. We got off work, dropped some Wendy's off for her grandma, then I drove to the neighborhood across from hers and parked on the street in front of a random house. Moving around was a little awkward but she came through like a champ.
Biggest would be my '82 F150. Bench seat, was like fucking on a couch. Loved that piece of shit truck... Smallest would be the back seat of an '09 Prius. Being 6'5 I consider this somewhat of an accomplishment. It didn't hurt that she was only 5'1, but hey, still an accomplishment.