To say I'm impressed with your electrical (and, for that matter, mechanical) knowledge is an understatement. It's guys like you who will keep these cars drivable if/when their electronics go bad--which I'm afraid might be the car's long-term downfall. I'm glad to hear you are shifting your focus from SRT-4's to the Crossfire--after 16 years with them I can see where it's a major change. We need guys like you to keep the XF's running.

Big picture question: Would it be possible to replace most of the Mercedes/Chrysler electronic parts with the Arduino / Real Dash / other aftermarket new parts to get the car running properly and pass state inspections/smog inspections if the factory parts no longer worked? I don't know how far you can go with this aftermarket stuff, so just wondering if it is able to give all the functions necessary to have a road-worthy / legal car.