The only opportunity for me in my area is for car sales, I have never done any kind of muster shop before. In the rules for bestmark it states to provide receipts, how do u provide reciepts if your pretending to be interested in a car?
A business card is typically the required receipt for a car sales shop. It's hard to walk away from a car salesman without him offering a business card. Even if you have to ask for a card, it's easy to get one.
If he hasn't given it to you already, snag one from his desk when he goes to get the sales manager.
Think of "receipt" as "what you received" in the mystery shopping context and it will make more sense than limiting the term to meaning "proof of purchase."