I also have a 2009 Z4 DCT with a IME0S DME. What tune do you have on your car? I had JB4 G4 but it was maxing out Fuel Trims and I was told it was because the DCT does not like piggy backs. I installed Wagner FMIC and AR Down Pipes and switched to a OFT Stage 2 which works great. I am wanting to install Meth and was planning to go the JB4 G5 route with Backend flash but can't find one for the IME0S. I tried creating one by copying from an INA0S but that did not work.
Would like to hear what mods and tune you are using for your Z4 DCT. Also, have you ever taken to the drag strip and if so, how to do launch? I am planning to go next week for the first time.