When a car company is able to back a unique de-sign with outstanding quality credentials, the result is likely to be a vehicle that stands out from the crowd. So it is with the Toyota Previa minivan. In a market that's awash with solid offerings from almost every major manufacturer - even Honda has joined the party - the Previa marches to its own beat. Whether that beat is entirely in tune with what minivan buyers want to hear is another issue. Are the unique elements of its design important innovations? Or, like 4-wheel steering, are they answers to questions no one has asked?