Imoport Muscle cars are the big daddies of the Import world generally having at least a 6-Cylinder engine and turbocharged. There are basically six of them: Nissan Skyline GT-R(R32-34), Toyota Supra RZ or RS, Mazda RX-7 (RZ, RS, or Enfini), Nissan 300ZX Fairlady, Honda NSX-T Type-R, and the Mitsubishi GTO Twin-Turbo AWD. Sadly the only car that is still in production and still has the power of it's predecessor is the Nissan Z. You could make arguments for the new Mazda RX-8 but it's nothing compared to the third gen. RX-7.
A 2001 Nissan Skyline GT-R R34 Nur Edition, Now that's an Import Muscle car