You will want to look into the legalities of that, as in many states "kick-backs" are illegal, I think it stands in same realm as collision.
From my standpoint of being the operator (light duty), I will not do business based on any kickbacks of any kind, you want my breakdown customers in your shop, ya need to have a reputable shop. Where I recommend to my customer for service is reflection of the company I run for, I'm not taking them to Joe's Barn Garage just so I can get a few bucks. Integrity is everything to me.