Does anyone know of a source for the foam grommets that go in on either side of the A/C vents? I bought some a long time ago but can't seem to find them anywhere now. Any suggestions would be greatly appreciated.

 

Someone else on TGO suggested rubber "O" Rings. Harbor Freight has O Ring assortments pretty cheap.

You might consider thin Felt fabric, from hardware stores. Probably near the picture hanging stuff.

I have not tried it yet.

 

Not a "factory" fix for sure, but I pulled my vents out (without breaking the tabs), scrapped of the residue from the original felt, and used some Velcro fuzzy tape on my vents. I stopped the sag.

 

I just popped all mine out. All the foam jobs were folded over so it probably has been like that since the factory. I've had it since 1997 and they always flopped around, now I know why. Took less than 5m to pop them all out today and put some green AC o-rings on them because that all I had, works great. Just enough drag to keep them in place but not so much it feels like I've got an early 2000 Kia.