One thing I learned when researching the "value" for the '91 Westfalia 
     I bought is that the Kelly system is much more liberal than the NADA 
     book.  I ran this car on the Kelly Internet thingie and got a value 
     just under $20K, yet the NADA book (which my credit union uses to 
     establish loan values) brought it down to $12,900 retail ($500 less 
     than the agreed-upon selling price).
     
     So, depending on your motivation and situation (and year of the car - 
     I don't think you can find anything from NADA for older cars), realize 
     that there are these differences.
     
     -Blaine