When assessing auction car prices, you must prioritize the Vehicle Grade (Auction Sheet), which typically ranges from S (New) to R (Repaired). Key technical factors include Mileage (low mileage significantly increases value), Engine Displacement, and Transmission Type. For B2B buyers, it is crucial to verify the Chassis Number (VIN) to confirm the exact production year and avoid 'year-flipping' scams. Additionally, check for Emission Standard Compliance (e.g., Euro 4, 5, or 6) to ensure the vehicle can be legally registered in your target country.