I recently bought a new 2006 AWD sienna with run-flat tires. I've contemplated taking them off once they've worn down, or even selling them now while they still have all their tread life remaining. Can the rims support regular tires if I choose to wear out the run-flat tires? If I obtain four new tires, can I throw a donut tire in the rear seat well (losing the store and go option), and rely on the donut tire for a temporary spare? If conventional tires are used (with new rims or with run-flat rims), will the tire pressure system/light be an issue?