When I wrote off my 98 GTS they told me 'book value' was $45,000. After we laughed a bit they offered me $56,000 (with only $6,000 for the mods). Using
Canada Used Autos, Cars, Trucks, Boats, Motorcycles Online Classified Ads - AutoTrader.ca I showed them 3 ads for $70-75,000 and eventually got them to cash me at $66,000 plus taxes. This is in Canada and I went into the isnurance office with a feature magazine article and a Car Show First place trophy of my car.
I paid $55,000us for my '01 with many mods and cost was an extra $4,000 to pick it up in Ohio then drive it back here. Nice holiday though.
Values often depend on reasons and I didn't mind paying more for my car because it had less than 10K on the upgraded motor, lightweight brakes, exhaust, supercharger with new clutch and tires. It also went 10.5@139mph and took trophies at the V10 Nats. I've since had it featured in
Domestic Driver - A bi-monthly online magazine featuring Chrysler, Dodge, Ford, and GM Cars from 1980+ and received a prestigious first place award in a car show.
Only stock cars can be easily valued. Color also makes a difference. So does the country it's in.
For insurance purposes everyone should document their cars for value, unless you're happy with 'book value'.
Ted