Originally Posted by mlhj83
Any remap is detectable, but not by the dealership. If there is a major issue with the engine or ECU, the ECU data does get sent back to BMW M for scrutiny and any tempering will be picked up even if the remap is no longer there. If you manage to convince any reputable tuner to state it in writing that their remap is undetectable, then I would surely like to know. There are still logs that show data values have been changed, even when original values are put back. I had a DME malfunction and it was sent back to Munich before a replacement was sent back 3 weeks later. I didn't have a remap however. Nothing wrong with remaping, but one has to accept a certain level of risk.
But even if you play by the book (no tune): every M3 launch control is also irreversibly logged "and we can see that"
my dealer at trade-in of my M3 for a 1M). A 'clean' record favors trade-in chances.