use some thin double side tape.
That wont work..the problem is the sub wont fit in the box all the way and that rubber is the exact thickness o allow me to use longer screws and still be air tight
ill take it 13 shipped prority LMK what your addylooks like you just need to sand/cut the box out a little more so that your sub will fit all the way down in the enclosure....I have a few (not really extras but I'd be willing to sell one to you if you really need it). I can't go any less than $13 through paypal though. Shipping will take $4 to $7 of that. LMK.
V.