A friend of mine works at RCR (race car replicas) in at grosbeck and 16 mile. They made and atom fighter powered buy a SS cobalt engine. Its cheaper with the same performance, And its local. The atom is deff badass tho.
http://www.race-car-replicas.com/
http://www.race-car-replicas.com/rcrproadster.html
http://www.superlitecars.com/roadster_spec.html
Find me one in the states
They are available here and have an assembly plant here. They use the ecotec motor now as well. My brother was going to purchase one, but then he realized he could not register it as a street legal car.