This one is a bit acrobatic and requires some upper body strength from both partners. The woman lays her upper body face down on the car hood or trunk. The man lifts her legs up and holds them spread apart as he fucks her from behind. The woman can also wrap her legs around the man's waist (crossing her ankles behind her back) for extra support. This positions gives the man a nice view of his partner's backside, and is good for G-spot stimulation.

With the door open, either the man or woman sits in the car seat, facing outward. Their partner kneels outside the car between their spread legs and goes down on them. If caught in the act, you can pretend you were looking for a lost set of keys.

The guy seats himself on the motorcycle as usual, and the woman mounts him by sitting on his lap so they are face to face. She will need to wrap her arms around him and hold tight to maintain balance. If she has rear foot pegs to brace against, the woman can control the depth and speed of penetration by riding the man's cock and bouncing up and down on it. You don't want to bounce too much, though, or you'll wear out the shocks - or fall off the bike. This is the best position for the guy if he wants to actually see where he's going.

Mount a large dildo with a flanged base to the front bumper of your car using bungee cords or tie-down straps to secure it. Or use a dildo with a suction cup base and apply it directly to the bumper. Step up onto the bumper and plant your feet wide on either side of the dildo, leaning forward onto the hood for balance and support. Lower yourself onto the dong, insert it, and bounce up and down. When you're done, remember to remove the dildo from the bumper, unless you want to attract attention while driving.