Kelley Blue Book Used Classic Car Values. If you are a fan of a classic car to collect or purchase, you can rely on the classic car blue book. It is simply your best guide when it comes to making negotiations and deals. Study up the value of a classic car is always important because it makes a huge difference in getting the best deals or being doped. This is perhaps as close to Wall Street as classic car enthusiasts get. Run by the Historic Automobile Group International, the HAGI Index tracks classic car values as compared to other luxury investments such as Art. They claim over 100,000 transactions are taken into account from classic car specialists, private sales, auctions and dealerships. Classic Car Price Guide. Hemmings works with Hagerty to help give you the best information regarding the current pricing of classic cars. We supply listing data to Hagerty’s Valuation team to help for the most complete available picture of pricing available.. 2020. By accessing our Service,.