I am thinking about possibly buying some downpipes and midpipe for the M4, but I would imagine the car will requiring mapping? Are there any "Reputable/Capable" mappers in N.I.? I had no issue when getting any of my Evo's mapped as there were tried and tested companies available but I don't think I have ever heard of anyone who maps Bmw. I had a look online and cant find anyone in the mapping industry over here that doesn't have bad reviews and seem to all be "felt spec bora diesel mappers". Need someone trustworthy that has plenty of experience.