I have their service plan for my 2012 ML350, and it costs £49 a month for two years and two services. I have extended it three times already, and each time the price has remained the same. They are quite persistent after the second service. My estimation is that each treatment will cost £588. Everything from transaxle service fluid and filters to cabin filters, extra work when it's required, and brake fluid changes are all part of this. It seems worthwhile to me. As an added bonus, their service plan usually includes a free courtesy car, so I can simply leave my own car at the dealership and take advantage of theirs. Plus, I've utilised the free Mercedes recovery service on many occasions, both domestically and abroad, in Europe. Whenever they discover problems, I have the option to either fix them together or bring the report to another garage to have it fixed there. Because the vehicle is already in their possession, they are often willing to negotiate a lower repair price than a local garage would be willing to provide. This is because they value their company and do not want to lose customers. Keep the rental car until yours is fixed if they are unable to do it on the same day. While they were mending mine, I got a new GLC for three weeks. Now that I sound like a Mercedes salesman, I'll end here 🙂