You can adjust the trunk latch to hold the lid down tighter as that will help some, but upfiring is going to beat that trunk lid to death.
It was 75degrees in my garage yesterday and today, worked in jeans & a t-shirt //content.invisioncic.com/y282845/emoticons/biggrin.gif.d71a5d36fcbab170f2364c9f2e3946cb.gif You guys are seriously insane if you did all of this outside //content.invisioncic.com/y282845/emoticons/crazy.gif.c13912c32de98515d3142759a824dae7.gif
If we have a Chicago CA.com get together this year I'm sure Tommyk will have his TL, so you can get metered.
Props to Pioneerpimp for hookin you up!!! I wanted a little more than "free" to do it, but would have gone through the back seat and built a bigger box that was rear firing, so I had to get something for all the work involved.