This was an ad for Volkswagon's Phaeton (which didn't sell very well). It's shadow puppetry, rather than animation, but I think it's a good example of how you can get good visual readability with just a silhouette. I feel that the greatest amount of form detail can be extrapolated just by looking at a silhouette.
http://www.youtube.com/watch?v=KQiIMz6nf-M
Here's another one, not really an ad, but another bit of excellent shadow puppetry, this one performed by Raymond Crowe.
http://www.youtube.com/watch?v=hZfNA9Kx ... re=related
Shadow Puppets
Shadow Puppets
(Win7x64, TVP Pro 11 32-bit)