I worked at the Buick/GMC dealer for a dozen years. I was a Service Advisor. I thought of myself as a shop foreman. Talk to the customers, schedule the work, Run cars in and out to keep the shop full and the tech's busy. I did sell service but we (service manager and I) didn't sell what wasn't needed. Back then we would do cooling flush, wheel bearing repack, transmission service, and engine tune every 25,000 miles. We had a lot of happy customers that went on trouble free vacations across the country. Tire rotation and alignment as needed. I am not a believer in rotation at every oil change. There is over 60,000 on the wife's Envision with the original tires that have never been rotated. No uneven wear and it is a all wheel drive. It's time for a new set before winter though.