Most vehicle dealerships subscribe to the Canadian Black Book, so if you want a truly free valuation without providing too much personal information, take your vehicle to a dealership and tell them you only need a trade-in value.
A lifetime diamond guarantee is also available as long as the ring or jewelry piece in question is regularly inspected, and couples interested in more elaborate jewelry will appreciate the company's trade-in policy for upgrades.
Typically, used car dealerships purchase vehicles from auctions, off lease or as a trade-in, invest a certain amount of money to make the vehicle road worthy, and then resell that used vehicle for close to its market value.
Keep in mind that while this service through GMAC/GM Canada is free, you can only get a Black Book trade-in value if you provide a new General Motors vehicle you want to purchase as well as an email address.
According to Buying Advice, which has researched trade-in values from both the Black Book, Kelley Blue Book, and NADA, Black Book trade-in values fall somewhere in the middle of Kelley Blue Book and NADA.