[Scoob]

I believe I found the problem - the top strut nut was several turns loose! I drove it at lunchtime and it started to make me nervous. When I got back to work I looked under the hood and happened to have a 22mm socket that worked well enough to tighten the nut. I think I got about four full turns on it without trying hard! I'll look at it again tonight and tighten both sides with the proper tools and hopefully I'll be done and get back to the alignment...

My questions that will never get answered: why did it start rattling when it did - I never even touched the top nut? Was it getting loose for a while and the camber change simply exacerbated the loosening?