I have been offered 2 brand new Continental Contisport 255/35 ZR19 M3 at a very good price, they are the original contisports, not the version 2 or 3. I think they are intended for the BMW M3, but will fit my A6 Le Mans. I'm very tempted but wondering if I might have an issue if they are not XL (extra load) rated, i.e. they lack the stiffer side walls which I think are recommended (not sure if mandatory) for the A6 C6. I'd welcome some opinions on this, as I'm very close to going for it !