The January issue of Roundel contained some letters about the engine software for the 335s. I have a 335i that was built in 04/07, so it falls into the group affected by the engine software release that is mentioned in the article. I just had my car serviced by the dealer. I asked them not to apply any engine software upgrades because the car performs wonderfully. But, I think the standard policy is to apply the latest updates when a car is in for service. The car has iDrive. Is there a way that I can see what version of the software is installed on my car without having to go back to the dealer to find out?
Only the dealer can tell you when the car is hooked up for diagnostics. The car runs better with the newer softwares. My 07 335 was pre progman 29.2 and my 09 335 is whatever software it is now. My 09 is just a quick, but much smoother and gets better fuel economy.