did mppk install at Crevier as well a couple months ago, quoted an hour's labor ($168) and for some reason they let me use the 10% off coupon/discount you get for checking in on yelp (tip, ask at the register when you pay instead of your SA… I didnt tell you that shhhh)… no complaints here
pkancel read all about it here… in short its a tune from the factory for the 335i that gets you more power, among other things
http://f30.bimmerpost.com/forums/sho...highlight=mppk