Toyota has sold small vans in the U.S. since 1984. But before the introduction of the Sienna minivan in the 1998 model year Toyota s minivans were decidedly different from the norm and found relatively few buyers. That was a most unfamiliar and uncomfortable situation for a company that is used to having its vehicles considered benchmarks in their class. The Sienna has remedied that problem and has given Toyota a solid presence in the minivan class. It is a vehicle designed for the North American marketplace built only at the Toyota plant in Georgetown Kentucky. Calling the Sienna the Camry of minivans is no misnomer. It is based on the Camry platform with the wheelbase stretched nine inches and built on the same assembly line as Camrys. The only engine offered is the 194-horsepower 3.0-liter V6 also used in the Camry. Although 1999 is only the second year for the Sienna there are some interesting new features. As before value-oriented CE popularly-equipped LE and luxuriously-appointed XLE trim levels are offered. But the CE may now be had with a left-side sliding passenger door and LE and XLE models have an optional power passenger-side sliding door in addition to their standard left-side sliding passenger doors. Dual integrated child restraint seats are available in CE and LE models. A 1999 Sienna LE with the power door has been my transportation for the past week. A conveniently-sized vehicle with easy access and plenty of room it s as quiet and comfortable as a Camry - a Camry with room for seven people. The ultimate Camry wagon? APPEARANCE: The first Toyota minivan was a bricklike vehicle resembling a shuttlecraft from the U.S.S. Enterprise of Star Trek fame. It was followed by the futuristically bubble-shaped Previa. The only space related to the Sienna is inside. Outside it is solidly in the mainstream of minivan styling with a short steeply-sloped hood well- raked windshield and long passenger cabin giving it a functional two- box shape. As with other contemporary minivans there are no flat body panels but it s not overly rounded. A character line on the side is one of the few straight lines on the Sienna. Crisp angles in the hood interestingly-shaped headlights and a well-defined grille give it identity. There is no indication of any relation to a Camry and little besides the corporate logo in the center bar of the body-colored grille to indicate that the Sienna is a Toyota. Functional gray plastic cladding on the bumpers and lower side offsets the body color and adds protection. COMFORT: Open the pod bay door HAL.... The power right-side sliding door is more than a gimmick at least for those of us who are limited to two arms that can be full of groceries or boxes. The door can be opened or closed by buttons on the remote fob the right-side B- pillar and the dashboard. A slight tug on the door handle starts the electric opening process. Inside the Sienna LE has the versatility expected in an minivan the unostentatious but handsomely functional materials of a mid-level Camry and Toyota high-quality fit and finish. Floor height is greater than that of a sedan but far less than found in an SUV. This week s test van has the optional second-row captain s chairs which recline fully and are adjustable fore and aft. They are near clones of the comfy front seats and allow a center aisle for easy access to the rear bench seat. The rear seat is split 50/50 and either side may separately be folded tumbled forward or removed. Ditto for the second-row seats. Cupholders storage spaces and vents abound throughout the cabin. Up front a single wide hooded pod in the dashboard contains the instruments and climate controls. A steering- column-mounted shift lever leaves flat floor space. Radio controls mounted on the steering wheel are new this year. SAFETY: The Toyota Sienna meets or exceeds all current and foreseeable future crash standards in the U.S. Europe and Asia. It has