SL55/63/65/R230 AMG: A lot of things mess up after the service.
Perhaps the vacuum circuit in your SL isn't vacuum anymore around the door locking. This might explain why those things don't work anymore. I have no idea if it can be related to your service, perhaps it's just bad luck.
As for the dipstick, I believe the SL55 doesn't have one standard. There is a plug to cover that hole, which the mechanic perhaps forgot to put back. They tend to suck out the oil via that hole (a no-no since the car has a double carter pan, but they all do it).
Good luck sorting things out, it may be less bad then you think.






