My God, Slashdot has gone to shit over the years. That kind of unresearched clickbait nonsense would not have made a post 10 years ago.
The aircraft in the picture is:
1. Too small.
Once you add armament and armor, the Bugatti would be a LOT slower. Probably slower than the Bf-109 that set the 469mph record.
To compensate, you'd need a bigger engine. The 109, which was a small fighter to begin with (half the size of a P-51 and a third the size of a P-47), was already running a big engine for its size and barely had enough room to upgrade to the DB605 during the middle of the war. This Bugatti is tiny. It's powered by two 4.9L engines that produce 450hp each. In 1940, the 109 had the DB601 with a displacement of 34L and produced ~1200hp. By 1945, the DB605 was up to 37L and produced about 1800hp.
The Bugatti wouldn't be big enough to run an engine that big, and while I'm sure one of you is going to ask "but it doesn't need to"... yes it does. If it's to carry enough fuel, armaments, and ammunition, it needs to have an engine that can propel it forward at combat speeds with all that extra weight, and an airframe that can hold all that. You don't get a lunar lander to the moon in Kerbal Space Program with a pair of solid fuel boosters, and you don't get an armed and armored fighter to loiter over Britain for an hour with two 4.9L engines. Not happening. Physics disagrees.
Incidentally, the 109's already small size was one of the major problems for the Germans during the Battle of Britain. It didn't have the fuel capacity to stay over London for anything more than 15-20 minutes and still be able to return to France.