Typically the terms and conditions of a sale at auction are determined by the auction company itself, and your rights are considerably more restricted than when purchasing privately or from a dealer. We would suggest looking closely at the terms of sale to determine your position, but a brief look at the auction terms for ASM suggests that your contract is with the seller of the vehicle and not ASM, and that ASM reserve the right to restrict or limit their obligations or liability to you as a buyer. We would suggest making contact with the seller directly, you can read more about rejecting a vehicle in our guide here - www.honestjohn.co.uk/faq/consumer-rights/ but again the nature of the sale via auction will limit your rights.