If you just straight up plug in the LED reflector headlights in place of the halogen headlights without doing anything else, the LED low beams will fail to fire up correctly because of the PWM on that circuit. That’s why it needs to be shut off with AlfaOBD (that’s what the LED light settings do- turn off PWM), or resistors need to be used like the retro shop harness. The turn signals and park lamps will throw bulb out warnings in the EVIC for the same reason. Also, the signature light strips won’t work, which are enabled with AlfaOBD, or fuse tapped on the retroshop harness.