As the average car on the road has never been older, it’s come as no surprise that all of those old cars need service and repairs—and the auto repair business has never been better. With that in mind, car dealerships are placing a renewed focus on making more money from their service departments, sometimes via questionable tactics, including classic upselling and proactively reaching out to customers about problems they might have but don’t even know about. “The front end of the store is sexy,” says one dealership CEO, “but we make our money in the back.”