Recently the alarm siren has started going off when I lock the car with the key fob. I've heard some MB models have a problem with a control unit getting wet and causing the alarm to activate. This car is a garage queen and hasn't been in the rain in years.

Any thoughts as to why this is happening?

Its possible that one of the car doors or trunk lid, or the fuel door lock actuator stopped locking, because of one of the small vacuum lines has broken.

The same thing happened when my drivers' door stopped locking with the key fob, it was one of the tiny vacuum lines that broke.

Listen for the sound of air leaking when you push the lock button, the car is going to need to be in a quiet place to hear the hiss.

Thanks. I think the problem is with the center console cover not locking.