i have an S4 and i have had only one problem, a water pump but it all depends on what mods you go with and how you treat the car.... turbo timer is smart but personally i wouldnt get a quattro A4, a lot of power is lost to the awd system but defiantly 1.8t over the V6... if your not planning on putting a lot of money into it, i would go with a jetta or gti