I suppose this could be considered more an infomercial than a question.
I travel on a ferry boat quite often and many times someone in a fancy Mercedes will leave their car, just to return red-faced when they are summoned over the loud speaker because their alarm system is howling down in the auto-hold of the ferry. We regulars just snicker and laugh --- tourists.
My first tip-off if you will was when the alarm on my car went off during a windstorm where gusts exceeded 50 mph. Subsequently, I joined the legend of red-faced ferry travelers when the alarm went off again during a rough sea passage.
I took the car to my dealer and told them --- fix it! They know me so they pulled the appropriate schematic and said, this is how to do it, do you want us to charge you for a half hour or would you like to do it? They know I love taking things apart so I grabbed the schematic and said thank you.
The GBS ECU is tucked up behind the glove box and it is a very simple control that can be adjusted by inserting the flat blade of a screw driver and turning the dial! The install setting is "6", and there are 11 settings --- 1 through 11. I don't know if 1 is the most or the least sensitive setting, but I will surely find out. So, without having done this, what I understand is I have to remove the glove box and then look up to the reinforcement brace (a tubular bar) where the GBS ECU box is mounted, and locate the small numbered dial slot hole that is used to make adjustments. I have the schematic but the Xerox copy the dealer made is very poor.
If anyone can add to this by way of their own experience I would appreciate it.