police stops as a proxy for social equality

I wonder what the incidence is of police stops of high-end cars around the world?  I'm thinking this could be an interesting measure of evenhanded enforcement/social arrangements around the world.  For example, notwithstanding its relatively high gini-coefficient, my guess is that most new BMW drivers feel they are as likely (or perhaps even MORE likely) to get stopped by the police.  I wonder how common this feeling is in other places.