While the car was travelling at a rate of about 45 mph, it did something I never experienced before. It started to shake, sputter and lose power while ascending a on a paved city street that had about a 20 degree uphill grade. The vehicle behind me didn't expect my sudden speed change and nearly rear ended me.. the engine icon appeared on the dash and I sputtered all the way home.

- Kalamazoo, MI, USA

As an example, when attempting to accelerate the vehicle onto a moving traffic situation the car hesitates/lags/delays before the engine catches, then it takes off like a rabbit when you don't expect it. This vehicle behavior has caused near miss accidents more than once when I was driving. It's not a delay which decreases a transient surge. It increases the transient surge as the car does not respond to the throttle for a half second then bolts forward with an awkward lurch and a slam. It's much rougher than a normal takeoff would be. It's not at all smooth. Some have described it as being rear-ended. The has been happening since I purchased the car in November 2010 many BMW owners have reported the problem to BMW as I have. The answer I got as well as many others from BMW was, "it's normal".

- Brookhaven, NY, USA