*It has come to my attention that the question was too general, and that there are many cars that meet the question's requirements. Everyone's answers have been really good so far.*

Have another hint:

Name two cars that were built in the United States, but were never sold in the United States.

HINT 1: They may have emigrated, but they left relatives behind.

HINT 2: Everyone has picked up on two Opels, especially the Opel GT. There is another Opel. This one, however, is the complete opposite of a sports car.