(MONEY Magazine) – For any car at any price, the 2004 BMW 5-Series' Active Steering is the year's top tech leap. Describing it barely does justice--this is something you have to drive to believe, or believe in.

Depending on how fast you're going, the system intelligently varies the steering ratio to produce a sharper or lazier turn relative to how much you're twisting the wheel. Especially below 10 mph, turn the wheel a little and the car turns a lot.

Sounds like no big deal, but it becomes miraculous the first time you execute a sharp U-turn or negotiate a tight parking slot. Suddenly the mental lightbulb comes on: Say good-bye to all that hand-over-hand shuffling, as a roughly half-revolution of the steering wheel produces a graceful swing into a space or around a stationary obstacle.

At what we'll call "fun driving" speeds (roughly 20 mph to 45 mph), the steering ratio slows but still remains quicker than your typical car. Charge down a snaking road, and the system executes lightning-fast directional changes without forcing you to saw at the wheel like an addled lumberjack. At high speeds, the steering becomes marginally slower than a traditional unit, boosting stability and avoiding any hint of twitchiness.

Don't confuse this with common variable-assist power steering, which merely makes the wheel feel lighter at slow speeds and firmer when going fast. The technology also links up with an electronic stability-control system for further advantage: If the car senses it's about to skid, an electric motor can automatically apply a subtle countersteer to stabilize the car.

If it all sounds like a scary overthrow of human control a la HAL 9000, rest easy: The BMW won't give you a bum steer. The system feels entirely right and natural in every driving situation. You do nothing different, as the technology goes about its business behind the scenes.

Expect other luxury automakers to mimic or match BMW's system. It's that good.