Took this Dinantronics tuner off my 2014 335i recently. There are no problems just wanted to try out the bm3 tune. This tune retails at $1,499. It comes with a stage 1 and stage 2 map. You can switch between the maps using the Dinan app for iPhone and Andriod. This tune works with all n55 engines. very easy to install takes maybe 30min.