I was once pulled over in my van in Utah for speeding- the cop was friendly and kind of joking about not thinking my piece of crap van could even go that fast.... until he noticed a couple of my black friends in the very back of the van and then immediately pulled his gun and demanded to see all of our hands.

I was pissed but my buddies said it happened all the time and to just be respectful and hopefully we'll leave with just a ticket. My guess is that blacks as a whole are more cooperative with police at stops and that the racism is even worse than these numbers suggest.