Aight, I've finally decided to install a video in jack to my nav system. Only thing is, I'm not sure it will work. I found pin-outs of the nav system and have a plan in my head how to wire it but since I can't find anyone online who did what I did, this is all just theory and I want to run this by a crowd before I do it. There are already documentations in other threads on the video pin-outs so I'm gonna assume that my video input is hooked up to that. However, this video signal will only turn on if the nav system thinks the car is in reverse. I plan to disconnect the reverse signal to the nav system. I thought about making it switchable but then I realized that as far as I am concerned, my nav system does not need to know if I'm really going in reverse or not. (If any of you can think of a reason why, please share!) Instead I will provide a switch and switchable power to the pin so I can turn the video on or off. I also noticed that adjacent pins are speed sensors so when I take my nav system apart I will measure the current and voltage of the speed sensor to see if I can make it switchable too so that you can enter nav inputs while driving. My guess is that 0V will mean 0 speed. I am questioning whether this will work or not because the nav system may use GPS to determine speed inside the nav unit rather than from the speed signal from combination meter. This will, of course, lock out the nav inputs from the GPS calculated speed. Also I am guessing that when I have the speed signal switched off, the navigation will have a harder time interpolating positions between GPS readings too. This will mean I will have to switch the speed switch back after using the nav inputs. I do think this is worth doing seeing how having passengers enter nav inputs while I'm driving can be very useful. Any comments on why this might be a bad idea are greatly appreciated!