That's one of the patrol cars for the Expressway in Japan. That section of the Police also use the 300 and 350Z's Those are the only roads that someone could really run while breaking to 80 KPH (~55 MPH) speed limit.
The power rating is because that's the highest horsepower a factory car can legally be sold at. And as I'm sure you know, that model (R34 GTR V-Spec) pushes out more then that! One of the loopholes, is that it can only be sold with a max of 280 as 'equiped.' Which is why if you bought an R34 GTR VSpec N1 (The model sold for racing, no AC, etc.) it comes with all the parts to put out well over 500 hp in the trunk!
A forum community dedicated to Nissan Skyline owners and enthusiasts. Come join the discussion about performance, turbos, racing, parts, classifieds, modifications, troubleshooting, maintenance, and more!