Judging by the quantity of spider webs that were still underneath the car after my cross-country drive from Arizona, and the iffy 2004 front and 2010 rear tire date codes, I'm pretty sure the Roadster had been sitting in storage for a few years before it was picked up by the dealer who sold it to me.
Despite the dealer's assurance that the car had received a thorough mechanical inspection, the tires were fine, and the Roadster was ready for the drive from Arizona to Kansas City, he was lying. (A used car dealer not being truthful? What a surprise.) My pre-flight walk-around inspection in the dealer's parking lot didn't reveal any worrisome issues, other than the age of the front tires, which displayed a lot of cracking in the rubber and were worn nearly down to the wear bars. I just needed enough rubber to safely get across country; I actually considered having the front tires replaced before heading back to Kansas City, but decided to roll the dice and gamble that the front rubber would hold up.
I was shocked to find the cords showing through on inside edge of the left front tire the first time I had the car up in the air in my garage:
I certainly dodged a bullet and was very lucky; I was cruising in excess of 70 MPH most of the way and went through a lot of road construction with rough pavement during the cross-country drive. I was already concerned about the lack of a spare tire in a Z3 M Roadster and actually packed a Z3 jack and a tire plug kit just in case. It's doubtful the tire plug kit would have been much help with the above tire.
Given the condition of the front tires, my first order of business was to replace them, but I wasn't enthusiastic about mounting spiffy new tires on wheels that had sustained a few too many curb massages. I also didn't want the car up on jack stands for a month waiting for the wheels to be refinished.
I looked at available aftermarket wheel options, but I couldn't find a 17" wheel style that I liked better than the OEM Roadstars.
I ended up replacing the ancient front Bridgestones with a pair of 225/45ZR17 Michelin Pilot Sport A/S 3 tires, and had the rear Michelin 245/40ZR17 Pilot Sports remounted on the new Roadstars. The circa 2010 rear tires will most likely be done by the end of the summer. I plan to bump up the size a tad and go to a slightly wider and taller tire to fill the wheel well a bit more and hopefully correct the speedometer error I have observed.