OK, here's the deal. You can play Forza Motorsport 2 on a standard-def TV with a wired Xbox 360 controller, with mono sound and you'll have a good time. The almost-complete build we saw in London is smooth, fast, realistic and comprehensive. But we've seen the same game, only totally different - and we want it.

Microsoft had set up a special playable unit in the corner of the press room and when we turned and saw it in action, an involuntary "wow" came out of our mouths. Three hi-def screens. Three Xbox 360s to power them. Surround sound speakers. A racing seat and Xbox 360 force feedback steering wheel. This is how Forza 2 should be played and we don't ever want to go back.

Above: We worked out the cheapest HD set-up to be just shy of $4,000 for this. Oh, it could do with some fans...

Sure, Ferrari 355 Challenge has done it before in the arcades, but playing the Nordschleife in hi-def (720p) on three screens is a revelation. We hopped in, switched off the driving aids and went for the full simulation experience. The enhanced peripheral vision really sucks you into the game, letting you glance at competitors or admire the scenery rushing by. And the sound is definitely 50% of the experience - the roaring engine and crunching sound effects are just as realistic as the driving physics.

While the game's graphics update at silky-smooth 60fps (with a slight drop apparent in replays, at least at this stage of development), the game's physics engine is running at 360 frames per second. That means Forza is judging bumps in the track that Gran Turismo 4 wouldn't even know were there. The result, coupled with some impressively complex tire physics, is a ride that demands as much care and concentration as a real car. You can turn on the stabilizers if you like, but for gearheads, there's only one option.