This is a big one how many pages is the report, how is it made, is it automated or hand made, is it court approved. What type of warranty or guarantee do you offer, is it USPAP compliant, does your report have comparables, do you give a free car history report, do you also confer with car dealerships and do you have any supporting legal documents. I can make a bet that if you ask those questions there is only a 1-2% of all diminished value appraisals and or reports that meet this criteria.