Just thought I would bump this one after my experience with the collapsible spare wheel yesterday.
Decided to "one hit" Port Grimaud to Worcester yesterday, which is about 970 miles and a projected 15 hours of travel.
488 miles and 7 hours in, the left rear let go in the fast lane - for some reason my Orange phone wouldn't let me connect to the Audi Assistance numbers (useful!) - so on went the collapsible spare wheel.
The manual states it is for short distance, emergency journeys only, but with no chance of sorting out a 20" tyre in the middle of France on a Sunday afternoon, we decided to at least try to get to the "Chunnel".
Another 480 miles later at 50 mph (and unfortunately another 13 hours later), the car is sat on my drive with the spare tyre looking as good as new !!
So, for anyone wondering if they are worth the money, my advice is just get one specced when you order your car !