....
But decided its totally irrelevant, following another alarm trigger, so I was outside moving cars and disconnecting batteries during Storm Christoph. I think its that time 
Have you tried disarming the passive sensor
or is it definitely door related.
The alarm looks to be door related, *IF* the trigger codes in the alarm ECU can be trusted.
Seat issues, next step is seat out to measure what is getting to the seat (seat is currently too low to be about to undo the connectors at the side). Though as the seat is in a usable position for her, its not a priority.