I run a 2008 Audi 4 Avant TDI B7, which I bought new. The dealer offered oversize 18-inch wheels and 235/40 tyres as a free option as part of an incentive package to sell the last few old body shape models. I have been following with interest your advice against such wheel and tyre choices and I endorse all you have been saying. Despite reasonably careful parking, the wheels have several unsightly chips, and tyre life is very disappointing. In addition, several tyres have had to be replaced following pothole incidents. I have been considering replacing with smaller wheels and higher profile tyres, but have been counselled not to. Can you advise whether there is any technical reason for not making such a change, and if not, suggest where one might buy suitable replacement wheels at reasonable cost?