Originally Posted by tom @ eas
Its not normal for coilpacks to be faulty on a 3-month old M3. It's likely one of the devices giving false errors.
OP needs to remove the aftermarket devices one at a time to find out what is causing the errors.
There's a few 2012 and 2013 models on this forum that went in with random misfire issues. I think some dealers replaced the coils (and likely the plugs) as the remedy. there was a mention this affected post-2011 cars, for some reason.