I have a 2000 Trans AM................the best way to have sex in it is to pull over somewhere on a dead-end country road.........roll the windows down, and take the tops off. I move my seat all the way back, and recline it slightly. Crank up the stereo to some appropriate music, and let her climb on top. She can get her groove on, leaning back and out the roof, watching the sky full of stars, grinding to the beat.
Works good, trust me.