I did this a few weeks ago in my 300TD.

If you want to turn on the front dome light, you should be able to use the wire in the driver's door sensor - the one in the door frame that turns on the dome light when the door is open. This is what I did, and it works wonderfully.

However, I couldn't figure out which wire to use for the parking lights, so I didn't bother with it... I'm going to go out right now to wire it to the little gray wire at the light switch though, thanks!

What's a radar perimeter detector? I'm guessing it's one of those things that beeps to tell you how close you're getting to things when backing up, am I right? Does it do the same in the forward direction? Where did you get it? For 19 bucks it could be a fun toy ;-).

__________________
'81 300TD Wagon 355k (Miss Diesel)
'83 300SD 180k
'84 500SEL 190k (Parting it out)