Championship Auto Racing Teams voted Monday to stage a new race, the U.S. 500, at the Michigan International Speedway in competition with the Indianapolis 500. At issue between CART and the Indianapolis Motor Speedway is the procedure for selecting the field for the Indy 500. This year, speedway President Tony George announced a radical plan to revamp qualifying for the Indy race, the only IndyCar race not controlled by CART. Mr. George said he plans to guarantee 25 of 33 starting spots in the Indy 500 to drivers from his own Indy Racing League. CART spokesman Adam Saal said such noted drivers as Al Unser Jr., Michael Andretti and Emerson Fittipaldi would compete in the new race.