With technology advancing every single day, there are so many things that the cars of today can do that were unimaginable a few years back. Of course, this means that you may have to face a few minor inconveniences every now and then, especially if you own more than one fancy car.
For this OP, that means that he sometimes forgets to lock his Mercedes because his other car which is a Tesla auto-locks when he walks away. We mean, if it’s that much of a hassle we’d be more than happy taking the Tesla off his hands. It’s the least we can do.