Allow me to explain.
As I mentioned in a post last night, the front of my exhaust pipe had become detached from the silencer. It was shifted sideways by about half an inch, so I secured it with gaffer tape and made plans to take it to be repaired properly in the morning.
It didn't make it.
Roar, roar, roar. The loud engine noise, which had appeared only last night and tipped me off to there being a problem in the first place, continued as it had done before. But then:
clink, clink, BANG!!!. What the ...?! Pulled into the kerb. A whiff of smoke rises from my gear lever, which I notice has suddenly rotated by 90 degrees.
Gear levers aren't meant to do that.
It turns out that the front end of the exhaust pipe had worked completely loose, and despite having no vertical play last night had fallen to the road, caught itself on the first irregularity it found and pushed the back end of the pipe upwards through the car with sufficient force to push the gear lever out of the floor and embed itself in the chassis. There's some irony in the exhaust pipe destroying a car, en route to Kwik Fit.
The AA man had to attack the exhaust pipe first with a hammer, then with a crowbar, and finally with a hacksaw, to get the car into a state where it could be towed without dragging metal across the road.
In hindsight I perhaps shouldn't have driven it at all this morning, and got a callout instead. That said, my level of AA membership wouldn't have covered them coming to my house - it would have added at least £100 to the price of exhaust repair. Looking at the removed section of pipe, the pipe itself seems to have been fine but the front of the silencer had sheared off, so I'm going to guess that replacing that would already have been on the margin of being uneconomical for a 1999 Fiesta. Ah well. I wasn't really expecting to take it through 2009's MOT anyway, so I just have to hasten my replacement plan rather than this being a completely unprepared expense.