I think it has something more to do that a higher % of people in detroit are driving 80s models cars with 24" wheels and when they take it in for an oil change they expect new brakes and 3rd gear to work again for no extra charge.
In Maryland with restaurants, if in PG county you'll notice a manger at tables 3-4 times more often then in Anna Arundel.
I wonder how they pull the stats for stuff like this, most stats are bullshit anyways.