The report, titled "Confessions from the Auto Body Shop," attempts to educate consumers on the collision repair business in general and how to select a good shop versus an unethical one. One of the shop owners quoted in the report dispels the notion consumers have that body shops are rolling in dough.

"At one time, body work was lucrative," he said. "But today, the well-run shops are realizing profits of 4 to 7 percent. And it's a very fine line between making 4 percent and losing 5 percent."

The report leads consumers to believe that their repairs might not be done safely or completely. "Body shops are supposed to restore cars to the standards of the OEMs, but they know from experience that doing so is going to be prohibitively expensive. Instead, they don't even consult the manufacturer's specifications and fix the car according to time-tested methods."

Also in the report is advice to avoid collision repair facilities that offer to "save the deductible" because they're trying to "scam" the insurance company.

The shop owners who were interviewed for the report also talked about parts, saying that some unethical shops will try to boost profits by charging customers for new OEM parts when they've actually installed used ones, or have substituted aftermarket parts for OEM parts without telling the customer. In other cases, the report says, the shops repair the original part, reuse it in the vehicle and charge the customer for a new part.

The report also advised consumers to be aware of shops "in cahoots" with insurance adjusters, saying that many shop owners try to "ingratiate" themselves with adjusters by detailing or painting their personal vehicles for free.

Read the full report on Edmunds.com

Read "Confessions of an Auto Claims Adjuster"