though there seem to be several supercar options like the mclaren MP4,ferrari FXX,and ferrari enzo that cost more than 500,000,consumers have few Alternatives-if and-for a mid to low 100,000 car like the forsche 911 turbo-particularly rs one that boasts near supercar.companies including BMW,Nisan,and GM have each performance to the porsche line,but their offerings do not present the prestige or variety of porsche's emblem or full lineup.