Honestly? Close to zero.
The strange bit is I've not seen many examples of this on the German forum at all. Isolated ones - mainly red cars - but nothing else. And we're now well out of 12 years paint guarantee, so I'd expect nothing from them, also because you can't prove at all why some cars have peeled and not others.
Looking at this, though, I'd say that car care is probably a factor, whether the car is washed and waxed correctly on a regular basis or not, and that Red has a significantly higher tendency to lose lacquer, with or without neglect contributing.
Many of the serious mile munchers over on the German forum are fine - one particular 450000km silver car I know is washed maybe twice a year but has no peel. Another is very much looked after but had issues with the headlight plastics discolouring with age and had a lacquer issue on the bonnet. That one is red. I suspect that Ultraviolet radiation is much of the answer. If so, then, in France and Italy, red A2s should be peeling all over the place...
- Bret