This car has one of the very early M272 engines.
Could have some balancer shaft gear problems and perhaps also oil leak at plastic plug at rear of cylinder head. Should be covered under CPO, and dealer should have records of whether these things have been previously addressed.
Thing not quite addressed as regards SBC, is that there were indeed some niggling problems, but once these are fixed they don't reoccur.
Actually the calipers are not really "quite conventional," as they feature basically spring-mounted pads, making need for grease to address squeaking go away. It's a cool feature.
Nice feature of Mercedes ownership is
http://www.startekinfo.com from which you can subscribe for free to use the Mercedes parts system and from which you can either order DVD of service procedures for your car or pay for a one-day subscription to download them. The latter approach is the better way to keep current on dealer technical bulletins (DTB) which are the same things that are called TSB for lesser cars. This stuff is fixed for free under warranty.
If you're going to do DIY, you need the tools, and having factory procedures is the most important tool to have. Don't even attempt an oil change without them.