I have come to the conclusion based on you posts that i should.
1. Tow it to Subaru to find the issue .
2. If it is the Brandt alarm and its too expensive to replace get it towed to a Auto electrician to put in a new alarm as Brandt alarms suck.

I was just thinking that if it is the Brandt, the thing is a death trap waiting to happen, as I was coming up to a busy intersection when the car cut out and l was lucky I rolled out of the way of on coming traffic!!!