Originally Posted by TerminatorX5

you are welcome. Even if you are not doing it this way, at least you know how it could be done using the OE parts...

The GPS unit that you are talking about - is it auto-sensing on the A/V input? does auto sense the type of video signal, PAL/SECAM or NTSC? If it is one of the chinese units that i saw on the ebay, it should be region-free and multisystem - i was considering it for the E39 that got traded in before that happened...

The reverse light is using Pulse Wave Modulation (PWM) and that means that the voltage on the light socket terminals is not steady 12VDC, but rather a wave, going from 12-14 VDC peak to maybe 6-8 VDC low, but in rapid succession, so the flickering of the lights is not visible to human eye. If a relay with a fast response time of the coil is connected to that source of power, and the power will go below and above the triggering point, the relay will flip the contacts and you may have the flickering issue, that has been disscussed already... to avoid that, either choose an alternative source of reverse activated power, or use a very slow responding relay, which will be too slow to react to the changes of the PWM and will hold the contacts engaged...