^That's how I bought my truck, with just a bill of sale. I think the guy said I paid like $100 bucks for it too, so I saved on taxes and 
. I'd say try it.
Only difference is he has to state that's it's a gift from a sibling so he can avoid having to smog the vehicle. The only exception is if the vehicle is already requiring a smog for registration renewal.
Other than that, it should go smoothly with no trouble at all.
