despite you having made the 64 rotations
Stole from the old radar spritesheet actually. My assumption was it doesn't spin because the player doesn't actually rotate the car, so even fixing the format probably won't fix the animation.
One day I might rework the entities to be composite. Layering a power consuming entity that has normal animations to spin the dish with a hidden car on the same spot. Then I could disable/enable the car based on powered state. Thats just the base idea I've always had, never really put a ton of thought into it.