I have a set of 4 Continental Sport Contact 3 sizes 255 35 19 all with over 6mm tread... They were on my RS4 and have only been used for just over 2 months...
There is some slight damage to the rim protection section (the wife does not know how to park) on all 4 tyres BUT none of the tryes have any cracking and have never had a puncture
Grab yourself a bargain - £200 a pair or £375 for all four.
All the best,