I had the large plastic peice under the fan ripped off from a tire retread (with a few smaller plastic peices broken as well. It happened a couple of months ago and I am getting ready to have it fixed. The parts are less than $100, labor with the BMW dealership is about $400+ ( the bumper has to come off to replace some parts.)
My first reaction is to go with the dealer who would know BMWs best I assume, but I could probably save lots of money with a body shop. Perhaps less then half of the labor cost.
What would you do?