i was going to do what madic did, but i use my trunk a lot so the foam stuff wouldn't hold up very long.
i bought some sound deadening material for my trunk similar to dynomat, called b-quiet (original) (
www.b-quiet.com) 90 sq ft for $99.
results were pretty good. not drastic or great, but did reduce noise.
i have plenty of the stuff left over, let me know if you want to swing a deal for some.
