How to appraise a car?

I have a car that was totalled in an accident. I am taking the person who did it to small claims court, but I have to figure out the market value. I have prices from kbb, nada, and 5 classifieds listings. I could just average them, but the problem is, there is a wide range in prices. I can exclude some listings or include others into the estimate and basically change the estimate to anything I want. And when using kbb estimates, is it the retail value, or the trade in value I should use in court? I tried to get an appraiser, but he said he just uses kbb. Is there a fair and common practice in a court of law for establishing the value of a used car?|||kbb.com or automotive.com|||dealerships use kbb well the one i worked at did/does..and they go with 1000 bucks lower then the trade value..|||http://www.edmunds.com