The Isettas original padding between the frame and body was kind of a fibrous webbing type material. I'm not sure what it was made from, but it was pretty crumbly when I was scraping it off the frame. For it's replacement I picked up a roll of 1.25" wide x 3/16" thick camper top weather strip from Metro Molded Parts (look under universal parts). A 25' roll sells for about 17.00. Metro Molded Parts also sells exterior rubber kits for the Isetta as well as the bumper to body seal, engine cover bumpers, and the stop bumpers for the front steering knuckles. Even though Metro is the manufacturer of these items, often Isetta parts suppliers sell them for less than you can purchase them for from Metro.