I had the same dilemma with the LT.  Here is what I used:
http://b-quiet.com/products-3/b-quiet-ultimate/

Although it made a big difference, I'd still really like it to be quieter.
  Road noise and wind noise are the 2 biggest factors.   I completely
covered the front floor area.  It did help with road noise and engine noise
(my 6 cyl diesel beast sits between the 2 front seats).   Now I can hear
the turbo whistle at 20 psi :)

Jason