We are in both the towing and repair business, so a few things from both views. Never offer an incentive to the tow company for work, any thing is considered a kickback and makes for bad business and may even be illegal depending on where you are located. Most often when our drivers arrive at a tow the customer already has a shop in mind, if they don't the recommendation comes from our dispatcher not the driver. We base the recommendation on the customers needs, convenience to job or home, the issue with the car ( does it just have multiple flats or something more serious,like died while driving) is it under warranty, we recommend nearest dealer. Yes we do tow to our own shop if it fits the customer's needs, we run the two businesses independently. We choose the shop based on it's reputation for honest work and customer service, because the end result is a reflection on us also. Let the customer pay the bill, it's easier and the customer gets a receipt they can send to their insurance company for reimbursement if they have towing coverage. You need to be willing to look at the car fairly quickly if the person is from out of the area so they can check their options and make arrangements for rides etc.