Twice a year interior shampoo and deep cleaning of the carpets, and a full body wax and power polish at the G.M. dealership where we bought it in 2013. Just turned over 65,000 miles in 13 years of ownership. That service costs $235 and it takes about 5 hours. I bring a good book, have breakfast for free in the dealership's cafe, and drive home. My service advisor, Marco, has worked there for 26 years, which is a long time to be with one employer. JIM.