just found this post and registered to the forum
I have an Audi S5 with a Hybrid TV tuner. Therefore there are 2 optional AV inputs which can be easily connected by just putting some Cinch cables to the red 12 or 20 pin connector. What could be better than using a Pi with these connections?
I bought original cables (look better than just soldering around) and could connect a DVD player but not my loved Pi. Audio works for both. So I guess it can be only the output voltage of the Pi (too low) or the resolution. I guess I have the wrong resolution set on the composite out. Nevertheless I could connect the Pi to two television screen without any problem (with the composite out of course).
I've seen that there might be a solution in editing the /boot/config.txt but I tried a bit but without success. I wonder if somebody has an idea how I could run the Raspberry Pi in my Audi with an probably special or not normal TV screen (all my other screens at home work well with the Pi).