Luckily, I was parked up at the time. Pressed the clutch pedal to the floor and heard something crack in the footwell

The pedal stayed down flat in the footwell. When I jiggled the pedal a bit side to side, a small (1cm) piece of black metal and an inch-long, oblong white plastic piece fell down into the footwell. The pedal came back up, but stayed down again when pressed. Like the spring mechanism had gone.
The breakdown chap said he'd seen this happen a few times on older Mk4's. Mine's a 2001. I'll see what the garage say the damage is tomorrow
