The bank-busting classic cars of 2020: Ten cars that smashed estimates at auction last year - but did buyers overpay for their four-wheeled desire? These 10 examples are the collectible cars sold at auction for the biggest fees above their estimated value Hagerty Price Guide uses auction results, independent sales and insurance values to work out market values These vehicles, all bought by winning bidders at online classic car sales in the UK, exceeded the book price The smallest winning bid over the market value was 11% while the biggest was a staggering 155%