Chase cars are a safety measure used to give pilots assistance during take off and landing of aircraft whose size is such that the pilot’s view is obstructed by the airframe, or part of it, and there’s a significant risk of hitting any ground obstacle with a wingtip.
Driven by highly trained pilot, those cars act as ground-based wingmen for the remote (or actual) pilots talking them through runway operations.
Both manned and unmanned planes rely on chase cars.
Chase automobiles, as the Chevrolet Camaro SS pony car seen in the following video, are used to supervise touch and gos performed for training purposes by U-2 Dragon Lady pilots at Beale Air Force Base, California, home of the 9th Reconnaissance Wing.