I had to replce my wiper motor and was unable to locate a new gasket to seal the wiper motor to the firwall. I searched through catalogs and local parts supply to no avail. My retired father in law Bill, who was a master plumber, suggested that I look at gaskets used for plumbing. At the local hardware store I found a rubber foam gasket that seals a toilet stool to the fill tank. It was the correct thickness at 2" inside dia. and 2.5" outside dia. It fits like a glove to the wiper motor and seals just as well. You may also use a bathtub drain seal. Although it is thinner, if you use several, you will achieve the proper thickness for the job. The cost? $1.49 for the foam rubber and $0.50 for the other. What a deal!

Good idea! will have to remember that little trick.