I have the S3 radiator which has 2 pins on the bottom of the radiator which rest into 2 holes in the chassis. 2 bolts hold the top of the rad. Should the pins have rubber mounts? should the top bolts have rubber washers between rad and metal bracket?
Any decent motorfactors will be able to supply grommets, of if you get stuck just get some grommet strip. They only cost pence and hardly worth posting.
Or try Maplins, noticed they keep a reasonable selection when having a look around the other day.And if you can't get washers for the top could slice a grommet in two.