Agree with Simon
we tend to emphasize the point that even new cars can pull lacquer here and there after time.
we build a small amount into the original quote for smart repairs upon removal, but will not guarantee anthing less than brand new, its not worth the risk of being stung with a full respray.
play it straight tell your customer from the off, get them to sign a damage waiver form if you are only involved in removing other peoples wraps.
we havent had any problem customers to date as we spell it out in writting prior to application/removal.