I found a full set of Michelin Pilot Sport A/S Plus tires, no patches, plugs or repairs, 6-7/32 tread left (9-10 new, so about 65% tread life left) They are 500 UTQG and Y speed rated.

Tire Rack sells them new for $243 each, and I got the entire set for $350. I think I'm going to move the Nexens to the Sebring since that car doesnt get as much hi-speed cruise time, and I'll put the Pilot Sports on Bonnie.

Maybe these plus the centric rings will smooth her out.