From the Larian website:
For months now, we’ve been working on a big secret. We can finally, and proudly, announce this new project:
"CaRPG" (working title)
Have you ever wondered what an RPG would look like when bringing it to the street? Well, here's your chance. In “CaRPG” you are a Cyrborg: half man, half car. During your dangerous journey through Mutant infested cities, you'll have to face uncountable adventures entangling your Cyrborg in the city’s intrigues, adrenalin-pumping car chases, challenging fights and all the cool features of an RPG. While being hunted by the various villains of a post-nuclear future, your goal is simple: to survive! About 12 different Alien races with simulated culture and complete daytime rhythm will make that very hard...
But you'll also meet lots of Allies that will offer their help if you help them out with many randomly generated Quests.
Mount over 60 different weapons on your vehicle and choose between 20 different cars, ranging from a very basic buggy (pun intended, see screenshot) up to very heavy trucks. Upgrade your character with several shields, armors, spikes, batteries, engines and so on. You'll start with basis of a steel-wire buggy, covered only with a leather hull, but look out for the chain-fence, full plate or titan armor plates! The weapon range is from a basic Katana up to multiple grenade launchers or even Ion canons.
When you get more experienced you will not only get faster and stronger, you also get bonus skills and equipment after reaching a certain level, such as special bumpers for escape saltos with your car, rocket boosters for high jumps or even gravitation belts for levitation. What more would a car want?
CaRPG will be fully 3D, using the same engine we'll use for Divinity II, will have full voiceover for all the dialogs, and steerwheel support.
Too bad it was their 2004 April Fool's joke. I would really like to have played this.