I run my 88 4runner with the topper off from late March through November. I have been looking for water proof seat covers for the back seat, but can't find them anywhere. Can anybody help?

I know this thread is old but in case you are still looking Wet Okole has waterproof seat covers.

http://www.wetokole.com/

Well
I guess there are quite many links scattered around here that provide 4runner accessories

I guess you should give it a try and find out which gives you the best deal !

Regards!!