Many, many, MANY times. I have a Lincoln navigator with tinted windows. What I discovered is people don't really pay attention to parked vehicles, especially large trucks with tinted windows. I'd have the air on and the windows up.
When you lower the third row, you have A LOT of room. I'm 6 feet and could lay down comfortably.
With one girl, we had our own "spot," in a mall parking lot, near the back during lunch hour. I'd back my truck in, and parked on an end spot so no one could park on that side, and she parked next to me. That way, no one could park next to us.
Other times, she would park one place and I'd come pick her up, and we would just go find a place to fuck.
We went all over: Walmart parking lots, strip malls, the beach, etc. Like I said, if you have a big SUV with tinted windows, most people aren't trying to look in your truck.
The most memorable rendezvous was one night at Chili's: we had been drinking with a few other people, and after everyone left, we got in my truck and went at it for about an hour, right in the Chili's parking lot.
With another girl I hooked with at my old job, I had my coworkers trained to know I parked away from everyone, in the back of the parking lot. (Everyone else liked to park close.) I'd always go to my truck to eat lunch.
What they didn't know is about 3 times a week, a co-worker would park next to me, and we'd fuck for about 25 minutes, and then she'd go back to work.
Think about how many times you've driven by a parked SUV and didn't give it a second glance? You'd be surprised what goes on behind those tinted windows... Lol