Well the Modus has been fixed
Fault was traced to a 'short circuit within the injection relay circuit'
Wiring has been repaired and Linzi has a much lighter purse
Garage couldn't give me a reason as to what had caused the problem though. Apparently there were no signs of water ingress
Oh and any profit they might have made on the job is going to be lost when they respray the drivers door thanks to the lovely scratch they put in it