You might try checking the Better Business Listings for your area.

An employer supposedly the sales manager at a dealership was sending
me email encouraging me to come in and buy a new car from him.  Upon
checking the BBB listing I found that his dealership had an "F"
rating.   I responded to him that if he explained to me the reasons
for their "F" rating I may come in and talk to him about a new car
purchase.  I did not receive a reply.

Joe