[fuschnicken]

Honestly, I haven't noticed any difference in sound quantity/quality with the ski pass removed. I have my sub mounted on the driver side of the trunk.

 

[fuschnicken]

Where on the driver side? Is it aimed to the end of the trunk or forward to the cabin? Have you tried placing it snugged to your ski pass hole?

 

[fuschnicken]

So far, my setup has cost about $2K. Not done yet, but that included the custom fiberglass enclosure for the sub. You might want to look into Stealth boxes though. If they can clear the rear strut, it might be your best bet. From what I've heard, they aren't that difficult to install.