Well, I've worked in Flash but never anything serious. I just never had the need for it.
One of my friends does miracles with Flash, but he does it just for himself. His interest in Flash is only academic.
It all depends on how much flash you want to use. If it's going to be a simple animation on the homepage than you could use SWiSH (
http://www.swishzone.com/index.php).
Since you were talking about cars that could present a few problems.
If you're going to draw them yourself you need the knowledge of drawing and animation.
If you're going to use real car pictures things get a lot more complicated. Flash works great with vector drawings but using bitmaps is a lot harder. Effects on bitmaps are harder to create. I've seen some fabulous designs with bitmaps but all of them were using Flash accompanied with Adobe After Effects (which are really expensive). After Effects were designed to create effects on movies and they work well with Flash but they also involve learning new things.