This is not very purposeful, besides having other players (online) wondering how you popped a wheelie off the line. You can have your car flip over in reverse also, or it may stand on its nose. You may have to rock your car back and forth by switching between forward and reverse throttle, but with the right touch, your FWD car should be able to do this trick also (going backwards of course), even though much less dramatic compared to going forward in a RWD car. With a front-wheel-drive car, simply get the rear hydraulics of your car bouncing and use reverse to pop a wheelie going backwards. You may flip over backwards if you take off too fast. Using nitrous once you shift into 1st gear will give you better results and may allow you to shift gears a few times before your car's front end drops back to the ground. If your timing was right, your car will surge forward and pop a wheelie at the same time. Having your transmission set to manual for best results, rev your motor all the way up and then shift into 1st gear.
You should now be able to release the R1 button and your RWD car (or SUV) should continue to bounce its front end. Once your vehicle's Hydraulics have been upgraded to Level 3, if you are in a rear-wheel-drive vehicle, get your front end to bounce continuosly by double tapping and then holding the R1 button (handbrake) and pushing up on the Left Analog Stick a few times.