The 20's are all Dunlops on the couple of dozen used at the plant as runner vehicles and by the ones at the PC. Our 4.8 non-sport is on Michelins (November 16th production date), but there's not a system for them, rather they take what they can get since they do not stockpile parts at the plant. It's a just-in-time plant (as most all are these days), which means the parts arrive (including wheel and tire assemblies) only a day or two before they are installed on the car in most cases. This is true of seats, exhausts, IP's, etc. also, but most items, unlike the tires are from a single supplier.