Jet.com offers the Dynamat Xtreme 36 Square Foot 9-Pack, model no. 10455, for $144.99. Coupon code "BACKTOSCHOOL07" cuts that to $134.99. With free shipping, that's the lowest total price we could find by $13. This sound deadening foam reduces external noise and improves the quality of your car audio.
Note: this coupon is limited to three uses per account. You can also receive additional discounts by waiving free returns or by choosing select payment options.