On my 2004 Z4, since I purchased it (as new vehicle), I have put in only 21K miles as a summer car. It has a puncture on the rear tire and I would like to replace all 4 tires. I want to know if I can replace RFTs with non-RFT, say the Bridgestone Potenze R50 RFT with one identical in size and rating non-run flat. Will the wheels accept the non-RFT tires? Any safety problems?