My wife and I bought a one-owner 2001 BMW Z3 a couple years ago with only 13,400 miles. It will cross 17K miles later this week. It has spent it's entire life in the Midwest (Chicago and now SE Wisconsin) and only driven from April until November. Always garaged. Should I be thinking about new tires because of the age of the tires or is it safe to go another 2 years or so since it hasn't seen much sun, little if any rain and no snow? Thanks!