Hi sorry bit late on he conversation but I have had the performance pack and exhaust retro fitted to my 2008 135i. Exhaust is brilliant. Power upgrade is good but very expensive for what you get. Also took the dealer 4 days to fit all the bits! Luckily agreed 1 day labour for the whole lot and they say they wouldn't do it again. Neither would I! Its got a small bit of turbo lag now but more than makes up for it with extra punch after 2k revs. Go for the exhaust but a cheaper chip. Not sure how necessary the extra powerful fan is. Oh and check your insurance first, mine decided they would no longer insure me! Shopped around and in the end got cover for £10 more than before. Good luck!