If you really get into open track days, the best thing to do is buy a set of rims and tires that are used only at the track. It is inexpensive to pick up a set of OEM rims.. A set of tires will set you back $500-$600 depending on what brand you go with. The Toyo RA-1 is a great R Compound tire and the Kumho Ecsta MX is a very sticky street tire.
Nikolas