"racing cars" actually would not be stationary. "Race cars" are the class of vehicle, which can be stationary. If the cars are racing, they are not stationary.
"High-speed" is ambiguous. It can be used to describe the class of vehicle, or it can be used to describe the state of motion of the vehicle.
"High-speed" is ambiguous. It can be used to describe the class of vehicle, or it can be used to describe the state of motion of the vehicle.