I am wanting to do the exact same thing. Make the cig lighter switched, so that when I have my Garmin GPS plugged in to it, it turns off when I switch off the car.

However, I got the knee bolster opened, but I have the feeling that the cig lighter wire doesn't go directly to the "30" post but first through the fusebox and from there the fusebox gets one large wire from the "30" post.

Could this be correct? Has anybody actually taken the cig lighter wire and connected it to 75X successfully?

 

Has anyone made any progress on this? I also have a Garmin GPS unit that I'd like to turn on and off with the car. If successful, could you please post a step by step? with color? and video? requiring 3D glasses? actually, just come to my house and show me? do it for me?
Thanks!

No, seriously, has anyone successfuly transferred the cig lighter to make it turn on and off with the car?

 

im not very sure but i always have my radar detector plugged in and it still runs after i turn ma car off but the car automatically shuts it off after a certain amount of time. i actually left my door partly open one night and the next morning i thought i was going to have to jump my car but i didn't.

 

if you know which one is the cig lighter then just put the wire on the 75x terminal. wouldn't a vag or bentley manual know which wire it is?

 

You can do a continuity test to see which terminal its in, and than take it back to the fuse box and do a test there as well using a volt meter that has a continuity test on it!

 

ive left my phone charger plugged in overnight and it doesnt do anything to the battery. idk how much power youre lookin to get out of it