I deal with insurance companies in settling total losses. Some companies use NADA blue book values, others do actual market surveys. In the case of passenger cars, my experience is that "book" retail is FAR above actual street price. Example, 1999 Audi A8, 99xxx miles. The NADA value is roughly $21K, local cars on the ground are fetching $12-13K ASKING price at local dealers. Take prices are likely 10% below that, so this is one that's running 50% below book. We have this Audi at my shop, with about $10K in damage, the seller wants $6K for the car, as it sits. If it was really worth book, it would make sense to buy it, with the local market as weak as it is, there's no point in getting involved.

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2002 Ford ZX2
2 x 2013 Honda Civics