Installed stage 1 package for 2014 m5 3 weeks ago, cost-$3499, labor $400. Dinan now charges $2999. Guess why? Because there is no noticeable hp gain, although they claim +91 gain. I have spent over $50,000 with this company over a 10 year period with 6 M cars. When I questioned them over this pricing practice and my disappointment over the seemingly lack of performance, I got a "we'll get back to you." No response yet. Price is probably heading lower. Most company's have this piggyback mod for less than half this price. And it may be with a company that gives a crap about their customers. BUYER BEWARE!!!!!