To reiterate, the airbags went off at very, very low speed, there was no forward impact as evidenced by nobody actually being contacted by any of the airbags as you might expect if you stopped suddenly.
I was thinking that the stump was low enough to slip under the bumper, but just high enough to catch the bottom of the suspension assembly. If this is where the sensor is waiting to detect a deflection then it has to assume that there has been some massive intrusion through the front of the car to reach that point and cause that deflection. As someone else has said, it's not the speed of my car that matters if you get hit by a truck whilst stationary.
So, poor observation on my part and bad luck. Cause of most accidents I suspect. First insurance claim in 30+ years of driving
The car is being taken away tomorrow, but I'm not expecting to see it again. From what I have read elsewhere the cost of fixing this will be £3k plus and it's not worth much more than that:
Front Passenger airbag
Driver seatbelt pre-tensioner
Front passenger seatbelt pre-tensioner
Broken windscreen (caused by airbag deployment)
Replacement steering wheel
Replace / reset crash sensors and control units
Reset engine fuel cutoff and engine
Any damage to suspension. Couldn't see any, but a full underbody inspection might reveal some.
Really quite sorry to have killed the old girl, had it from new, just over 6 years with very few problems and a recent clean MOT. Not the most exciting car in the world but a great family vehicle that allowed us to go out and do exciting things together. It never seemed to matter how much stuff you had, it always just fitted exactly.
I called in at the local Ford (S-Max) and Kia (Carens) garages today to see what they had to offer in the way of a nearly new alternative. I guess you sort of get used to what you have, but both those cars are dull as ditchwater inside and very old fashioned. So I'm now thinking another Grand Scenic or maybe a C4 Grand Picasso. Going to see what I can find this weekend. Some lucky car sales person is going to get the easiest sale of the year...
Final word re insurance company - Esure - Very efficient, very easy to deal with, arranged for collection, explained the whole process clearly. Just hope that they are not too evil and offer a sensible settlement on the car if it is a write off.