I added a multi-function rear-view mirror to my DeLorean. This added automatic, electrochromatic dimming, a digital compass, an outside temperature display, and Homelink (garage door / gate remote) buttons, all with a single upgrade to a part that was already broken in my vehicle. I've been very pleased with the results. While I installed this, I documented the procedure and took photos. Although my instructions are specific to the DeLorean, my instructions may be useful to anyone considering such a project.