Finally got round to checking my tyre pressures. I'm sure I should have done it a long time ago (10000 miles). Anyway, opened the fuel cap to check the pressure limits and found 16" and 17" but no 18". Useless! Whats the point of sending a car out of the factory on 18's and not providing info on the correct pressures. Surely its not going to break the bank for Audi to produce seperate stickers for different models. I'm running 3 pilot sports and one Pirelli P Zero. Any idea what pressures I should be putting in them, or is that a personal preference? The max rating on the tyres is 50 psi.