Now I know this may not be a popular option for Mercedes in particular but after hearing about close calls from my mechanic about them remote starts causing the car to start suddeningly when being service, I thought of this writing this post.
I myself have remote start and the works on my MBZ and it's very nice and wonderful feature and can you earn brownie points with ya date when the car is already warm inside for her (or him or whatever.). But many of us remote start owners tend to sometimes get a dirty look from mechanics because of the risk of it starting the car suddenly. I then realized the problem might be that most remote start system surprisingly does not come with a hood safety switch (like the on my car is equipped with.)
It basically is a switch that disables the remote start when the hood is raised, but don't worry, the car can still be started with the key and the car alarm ( the one that came with the remote start kit usually) can still be activated and deactivated even with the hood raised. Even though activating the alarm with the hood up may cause the alarm to go off when you close it depending on the system. With the safety switch, everyone is happy. No more caught hands when the best suddenly fires up or you don't have to disconnect the battery everytime you open up the hood (unless ya working on electrical stuff of course.)

Now as far as the remote door locks on a vaccuum power system... Just make sure they are very careful installing it or you will be plagued with door lock issues.