Installed a remote plug for the CTEK (www.amazon.com/gp/product/B002OHXX60) today. Had to remove most of the rear interior parts. Tapped the power lines here:


Here is the remote in place. Just cut the felt/board with a razor knife after removing from the car:

 

^ Did you have water issues in the trunk before? Just wondering with the amount of rust under there.

 

I haven't but I got the car in October last year with 53k miles on it. I just noticed the rust today as well.