Nissan's Altima is just right for some folks: smaller, more nimble and less expensive than the Maxima, Accord, Camry and other mid-size cars, yet faster, roomier, more comfortable and more sophisticated than compact cars. It handles like a sports sedan. For 2000, the Altima boasts a lot of changes that make it an even better car than before. For starters, it's nearly three inches longer. Fresh styling gives it a sleeker look. And refinements are everywhere, many aimed at reducing noise and harshness. The engine has been tuned for more power, the transmissions have been improved, steering response is sharper, and the suspension is firmer. If you can't justify the expense of a Maxima, the Altima is an excellent choice.