They connected the car to the diagnostic computer today, they hadn't looked at the car yet when I was told yesterday that they couldn't find the fault!!
The SDS showed an alarm module problem and it's replacement would be $450. I'll get the details when I pick up the car.
When I get the paperwork back I'll post the symptoms again and the repaired part. I asked for the old part back.

Also, when I went to the dealer today my salesman told me my loaner car should be free so I was credited that amount. If I was paying for a loaner car and the dealer was sitting on the car for two days before looking at it, that would have upset me.