A ridiculous Doom 2 mod turns all the grunting marines into vrooming automobiles, making the whole thing resemble a crude approximation of Destruction Derby or Twisted Metal.
The mod, entitled Byngu, debuted on the Zandronum forums where user mr fiat posted his bizarre creation (thanks, Kotaku). Evidently it consists of four classes of cars, each with their own advantages and disadvantages. There are also several custom power-ups.
Based on the clip below by Youtube user TheDarkstar64, the Byngu mod makes players look less like cars than marines larping as cars, as there's little momentum to the characters' movements (though you do sprint like the six-million dollar man), but it still looks fun and utterly chaotic regardless. Feel free to download the mod at the Zandronum forums.