@rednova
Yeah, that's a great approach, to use pre-rendered graphics. All the cars in Super Skidmarks are pre-rendered (in Imagine IIRC) so that gives you an idea of what could be possible.
Here's a Youtube video of some of the vehicle graphics in Skidmarks!Just be aware of what ChaosLord said - you'll be limited by the number of colours available to you, both by AMOS and by the underlying hardware. I don't know AMOS myself, but if it uses the standard hardware sprites, they're limited to 16 colours on AGA and 4 colours on ECS I think. Like in Skidmarks though, some careful dithering can give some very good results!