You've seen this stunt performed in movies before, and probably on The Dukes of Hazzard several times. When it happens in real life, the outcome can be much worse. The above is police bodycam footage from an incident near Valdosta, Georgia. Lowndes County sheriff's deputies were making an arrest on the side of a highway on May 24, and had a tow truck ready to impound a car. But a driver didn't see the activity going on and drove up the tow truck ramp at a high speed. The car launched into the air off the front of the truck, flew about 120 feet, and crashed into another car. The driver was taken to the hospital with serious injuries. The only other injury was to a police officer hit by flying debris.
WSB has more on the incident.
Update: I found a better quality video.