I was sold a used car, as is, and I purchased a warranty as part of the sale. It was deemed to have a bad engine and a bad transmission within miles of my buying it. I sued for breach of warranty, and the owner of the car lot denied that he sold warranties. I have the name of another customer who has a warrantee as well, and I want to introduce this as evidence that he routinely sells warranties. Is this admissible, and under what rule of the FRE?