Have you? A wheelie bar on a FWD car will lengthen the wheelbase and allow less weight transfer to the back of the car, giving more traction to the front wheels.
With FWD they are usually called wheelie or traction bars, I meant they physically lengthen the wheelbase because they are usually almost flat on the ground. "Traction bars" prevent the rear suspension from squatting and prevent the front end of the car from lifting. FWD cars don't actually wheelie.