In a car that will start, simply putting the key to the on position, or unlocking a door with the key will disarm the anti theft system. Max's car will not start; it is not operating properly.
I suggest two things;
1. Slit a rubber plug in the aft trunk area; Takes maybe ten minutes
2. Disconnect the cars battery, pull fuse 9, reconnect the battery and try to start the car.

What does Max have to loose, but twenty minutes of his time? If it proves nothing what did it hurt? What did it cost?
There are several examples here on the forum were members have been told by professionals that the SKREEM needs replacement, yet they simply pulled fuse 9, started their cars and drove away.