I have had a bad experience with BPC. Long story short, when talking with them about purchasing a stage II+ tune for my 335d, I asked if any tweaking could be done to the tune if I wasn't happy with anything - because it is expensive. I was assured that I would be happy with the tune. Well, when I received it, the car ran too smoky for my liking. It went weeks of them telling me my car was the cause of the smoking and very bad fuel economy. I even took their recommendation of taking my car to a dealer for some tests which proved there were no issues with my car. BPC offered no post sale support for a tune that cost me $1,000. I even requested a refund and that my DDE gets returned to stock, and all they could do is tell me there was something wrong with my car. I was always civil when talking with them. At this point they stopped returning my emails. I do not recommend BPC for any of their products, I am very dissatisfied with their post sale customer service and support - especially for the high cost of their tune, which I'm still wondering the true source of. I have completely re-tuned my DDE meaning I completely lost $1,000. Matt