[wrogers55]

I had the same problem on 318. Did a quick fix years ago that is still working as good today as the day it did it. I bought a couple of "foam" kitchen mats at Costco, dense rubber foam stuff. The bottom cushion comes out easily and it easy to undo the upholstery from the bottom by pulling the staples. I cut the the foam mat to fit, two layers of about a half inch as I recall, maybe a little thicker, and put them right under the seat cover with the stock foam below. Pulled the cover back over the bottom seat board, glued and stapled it back down. The difference was amazing and still is. I think the mats were something like 20 bucks each and you can get one seat out of each one. Cheapest mod you can do to make that much difference in an afternoon. Good luck.....