This is a tough one. I am going to go back a few years with something that we did when I was on the franchise side.
So, NADA had determined that a sales customer that utilizes the dealership's service department for all maintenance (and repair) work is something like 5 times more likely to purchase their next vehicle from that dealership. How do we get our sales customers to service here and therefore be much more likely to purchase their next vehicle from us?
We looked at the average trade cycle, and decided to offer free oil changes for that time duration. Basically, give the customer free oil changes to get them to service with us..and buy their next vehicle from us.
What we discovered was much different than what we anticipated. These customers would do their oil changes with us, but nothing else. If we told them they needed brakes, they would decline and head over to an independent facility. Tires, same thing. For the most part, we really didn't improve our service department by doing this. But it gets worse. They were also no more likely to purchase their next vehicle from us.
2 years later, NADA discovered that If the dealership subsidizes the program to entice customers to utilize their service facility......those customers are not more likely to purchase their next vehicle from that dealer. Who knew!?
I personally believe that the answer to your questions are with your customers. Simply put, ask your customers. Survey them, invite them in for a "round table discussion". As you already know, convenience and trust will be top 5 answers. There are other answers as well.
Sorry I can't add more here. Good luck.
