I've a 2001 320d that recently had the MAF changed at a local garage, all was great and I noticed a huge difference in low gear pick up, however I've discovered that when I reach 70-75+ mph I hit a flat spot. All acceleration stops and even declines if I go up a hill. Ive been informed by the garage that fitted it my ECU needs a software update to support my new MAF and only BMW dealerships can provide it. Has anybody else ever had this problem? can I get the software installed somewhere else? is there another soloution? Thanks for your help.