It's almost getting to the point where something not being shot with a DSLR is unusual!
This short "making-of" video shows the making of an add for the Nissan Sentra SE-R shot using 1/10 scale RC cars and Canon 5Ds. Interestingly, in addition to the Canon 5D, they also used smaller cameras mounted on RC vehicles. They mention that they used/tried some of the very small cameras (and show the GoPro HD Motorsports HERO Camera) but said that the quality wasn't good enough. They switched to a Panasonic unit - the AG-HCK10 I think - and said that they hoped the rental house wouldn't find out they'd mounted their expensive camera on an RC car [though if you want to keep it a secret, you might not want to put it on a YouTube video!]