Mister Ed, Yes, the car tires of the correct size will fit on the OEM rear wheel. Initially installing them on the bike, it's a bit tight, but nothing that can't be overcome with a plastic bag. There's a member on another board, maybe here as well, Monk, who regularly runs the Tail of the Dragon. If you ever watch him ride, you'll never question the handling ability of a car tire again. They work just fine. I run a Pirelli P1 run flat, 195/55-16. At present, my tire has over 14,000 miles on it and still has 4/32" of tread left. This is its 3rd season, and may be adequate to get me through the end of the season, but if not, Tire Rack can have me another here in a couple days for $130. The real advantage is the run flat feature. If you're taking long, long trips, you'll thank yourself many times over for the increased mileage and not being stranded with a flat. 50 miles at 50 MPH beats setting along side the road. If you're riding two up or towing a trailer, the extra weight capacity of these will make a world of difference as well. Good luck and ride safe.
