I replaced the rotted foam surrounds on mine which was super easy and quicker than other mods I would have had to make to fit different subs in the same area. The new foam surrounds were like $12 for the pair ..off ebay. Sorry, I don't remember the size or seller. I just used Elmers glue from my kids bottle. I know they say use speaker glue, and I have in the past on other speakers, but I was out or couldn't find it ...anyway it works just fine in a pinch. I think the whole process too a couple hours.

That was like 6 years ago and they still sound great. It's a good way to go if you aren't planning on updating the stock system. I've replaced a lot of rotted foam surrounds on old speakers. It's kind of a fun to do.