What does removing this bolt do?
 

Trying to install HID kit. Need to run a few wires (with connectors attached) between the battery compartment and headlight housings. Easiest way to do this? By removing that 13mm bolt will the whole "basket" or metal bowl behind the headlight come out giving me more access?

http://forums.pelicanparts.com/uploa...1390425086.jpg

That bolt holds part of the bumper support bracket underneath.

The headlight buckets themselves are welded into the fenders.

To pull through 1 or 2 small wires you should be able to sneak them through the existing harness from inside the trunk.

If you are adding several more wires you may want to drill new holes in the back of the bucket and pass through that way.

If you add new holes be sure to isolate your new looms with a grommet similar to what Porsche did originally.

This will avoid any chaffing plus it will keep moisture out of the back of the light bucket.

Cooper

The headlight bucket is welded as part of the fender assy.
Your bolt is probably holding a bracket for the wiper fluid or gas overfill tank. (you don't mention what year car)
Even removing the bolt will not leave you a hole as big as the one you're already looking at (drain hole[missing the tube]) Why drill another hole?
Keep in mind that that area is subject to wash from wet roads - that's why the drain tube was originally there.
Bill K

That is the Kingpin bolt holding up the right suspension of your car. Removing it means your car falls to pieces. NOT.

AKA Jesus nut. Like on top of a helicopter rotor...