Bought a 2007 RT from my local BMW dealership in August, my first BMW. 5 weeks later the problems started and it's happened 4 times now. At lows speed the revs die and the engine cuts out , no warning lights come prior to it dying, sometimes it'll start back up straight away but twice its turned over and over and over but has required a jump start to fire the engine back to life. It needed jump started the first time it happened. BMW replaced the battery after that foc but it happened twice in a fortnight in November, so they replaced the alternator etc this time. On Thursday on my way home from work on the motorway it briefly lost power at 70mph which it's never done before , once off the Mway into 30's it died . Called BMW Emergency Services, they sent a car mechanic... All the could do was just jump start it and check voltage battery was about 12+ & 14 with the engine running....I've covered 4000 miles it's got about 26k on it and the only thing I've done since I got was change the plugs to iridium ones ( which was suggested might be a problem by the car mech ??) Any idea's or suggestions of fault before it goes back in next week to garage