Most dealerships and businesses in general know that it's bad practice to bad-mouth your competition. That being said, I know of and have heard plenty of salespeople and managers using their online reviews to help close a deal by comparing them to their competitors online reviews. This practice is similar if not exactly the same. You are leveraging negative comments about your competitor left by other people (who you are representing as real - we all know fake reviews exist) to your positive reviews (you aren't really showing people any negative reviews about your dealership, are you?) in an effort to "sell" yourself and your dealership. So, while this isn't talking bad about your competitor directly, it is indirectly, and what you say can now get you in some deep water.

In a precendent setting ruling, an Alabama car dealership has been awarded $7.5 million dollars due to slanderous comments made during a close to consumers by both the salesperson and sales manager. Apparentley, the dealership's competitor was owned by an Iranian-born but naturalized U.S. citizen. The sales manager told at least one couple while attempting to close a deal that the competitor was "helping fund insurgents there and is also laundering money for them." The salesperson was also accused of telling the same couple that the dealer was "funneling money back to his family and other terrorists..." and that he has a "brother over there and what you're doing is helping kill my brother." It is also reported that the competitor was frequently referred to as "Taliban Toyota".

The jury awarded the Alabama dealer  $2.5 million in compensatory damages and $5 million in punitive damages after deliberating for 3 hours.

While this is certainly an extreme example, it bears watching where the "line" is. This had more to do with a leveraging of race, stereotypes and bigotry but there's no telling what future lawsuits outcomes would be utilizing this ruling as precedent.

I find it astonishing that, it appears, the sales manager, at least, is still employed at the dealership based on the statement that neither of them were available for comment per a "dealership spokesman". 

I think there are now 7.5 million reasons to add prohibiting the "bad-mouthing of your competitor" to your employee handbook.