I spoke to the insurers on Wednesday and the driver of the car I made contact with was claiming that she had stopped and I hit her with such force as to shove her into the car in front. She also now apparently has whiplash.
My insurers have spoken to the driver she hit. He is saying that she hit him twice - the first time really hard and the second time (when I made contact with her) was relatively gentle. So it looks as though she's going to be liable for the larger share of the damage. I'm sure the insurers will also be looking closely at her whiplash claim...
My car's gone into the garage. It's likely to be a couple of weeks before I get it back. I've been given a courtesy car, which is horrible. It's a little underpowered, cramped, uncomfortable Ford Fiesta.