It's the newer model. The one that runs on trash. No plutonium needed.
The ad reads, "movie accurate Plutonium Reactor (Part I style) ".
The garbage fuel system was introduced in the end of Pt. 1, but if you look at the ad for the car, you'll notice it doesn't have that wierd, white, top-of-a-food-processor-looking bit that says "Mr. Fusion".
That's pretty cool, though. If I had the money, I think I might actually buy it, straight away.