WANNA LOSE WEIGHT without unbuckling your seatbelt? Drive a 1988 Mitsubishi LS Wagon minivan over normal highways and streets.

"Normal" means potholes and bumps, and unexpected dips and curves. It means almost any street in the District of Columbia, Los Angeles, or New York. Forget those super-smooth test tracks. "Normal" means real.

Okay, climb into the minivan, crank the engine, and give it gas. Whoooaaa! Ride 'em, buckaroo! Hold onto that steering wheel. You're tilting to the left, tilting to the right. Left-right, left-right. Auto aerobics!

Rear passengers, listen up: You're gonna do the bump 'n' whine. Works like this: LS Wagon hits a bump. Rear passengers bounce up, come down, whine. Up-down, up-down, whine, moan, groan.

Alright, everybody, altogether now: Tilt to the left, tilt to the right, up-down, up-down, dy-no-mite!

Talk about a topsy-turvy, tippy vehicle!

Vans and minivans, being members of the truck family, usually have less-than-desirable ride and handling. But the LS Wagon's ride and handling are close to ridiculous.

Much of the problem stems from putting the engine behind the driver, which creates weird weight distribution. The test van's rear-wheel-drive layout and hard-knock suspension system aggravate the situation.

If Mitsubishi could find a way to stabilize this otherwise excellent vehicle, it conceivably could overtake Chrysler's Voyager and Caravan in minivan sales.

But, alas, the LS Wagon is no match for Chrysler's smooth-riding, good-handling, front-wheel-drive minis.

Extra gripe: That oddly placed engine creates a horizontal, wall-to-wall hump in the front of the minivan, a kind of Berlin Wall on wheels. The driver and front passenger have no free access to the rear of the vehicle.

Praise: Even with that space-consuming hump, the seven-seat LS Wagon has one of the best interiors on the market. The two center seats, buckets with armrests and headrests, can be moved backward or forward, or swiveled around.

Also, despite the hump, front-occupant legroom is commendably ample.

Cabin ventilation is terrific, thanks to rear windows that actually open. Rear climate control is tops, too, because of separately controlled rear heating and cooling units.

The instrument panel is well designed. Interior fit and finish are impeccable.

Head-turning quotient: Matter of great debate. Supporters think it's cute. Opponents say it's ugly as sin. I vote cute.

Acceleration: Pretty decent. Power comes from a 2.4-liter, single-overhead-cam, fuel- injected engine, rated 107 hp at 5,000 rpm.

Sound system: Electronic AM/FM stereo radio and cassette with four speakers and sub-woofer, by Mitsubishi. Excellent.

Mileage: About 20 to the gallon (14.2- gallon tank, estimated 274-mile range on usable volume), running with mixed loads (one to five occupants), with heater on part-time. Rolling over the bumpy streets of the District of Columbia and the highways and byways of the Great State of Virginia.

Price: $16,438, including $1,530 in options and $219 destination charge. Base price is $14,689; estimated dealer invoice, $13,000.

Warren Brown covers the auto industry for The Washington Post.