My ST is all stock, but at 16K miles it looks like the stock tires don't have a whole lot of life left in them. I am very happy with the way the car handles and feels in corners now, but I live in fear of potholes and other road irregularities, as the stock tires (Bridgestones) don't have much sidewall. I am also rapidly approaching retirement, and I would like to use this car for road trips and such when I have more time. I don't want a busted tire and/or rim ruining a trip, but I don't want to give away too much in the way the car handles. Should I be considering a smaller wheel (16" or even 15")?