I've seen two cars at our place, a brand new M3 CSL and on another occasion a ZM3 had AP Racing brake mods, suspension mods and the "visual appearance" was changed from standard, which voided the warranty.
I doubt they could tell whether the ECU map has changed but if his car ever needed a ECU under warranty he would lose it.
To take care of a brand new car which such passion then to lose the warranty is crazy! Then again, he did add he is very particular as to who works on his car so maybe he doesn't go to main dealer for repairs.