We have made, yet, another change to the tires we use.  Last couple year we used 275/35R15 Hoosier A6, but it was time to make a change and we are now on 255/40R13 Hoosier A6.  The car seem to be about as fast, but we no longer have the rollover problem. The car is 1" shorter and6lb lighter in each corner.  The wheels are 13x10 and are made by Real Racing wheels.