The Ford Probe is one of the success stories of the year. Everyone wantsone, but few can find one. When they do, they pay top dollar.

The Mazda MX-6 is Probe`s cousin. Not everyone wants one because lots ofpeople don`t realize it exists. Finding one is easy, but you`ll still pay ahefty sum, because while the MX-6 and Probe are relatives, the Mazda modelcarries a higher sticker.

Both cars are built at Mazda`s Flat Rock, Mich., assembly plant.Production is divided two-thirds Probe, one-third MX-6. Don`t shed tears forMazda. They aren`t building Probes for free for their U.S. partner.

Like the Probe GL, LX and GT, the MX-6 comes in three versions-DX, LX and GT, the latter its turbocharged, high-performance model. That`s the one wedrove.

The front-drive MX-6 2-door coupe is built on a 99-inch wheelbase and is177 inches long. Ditto Probe.

Though both come from the same plant, Probe and MX-6 styling differencesavoid the clone tag. Both are low slung 2-door coupes, but Probe is a bit moredramatic, a touch sportier, while MX-6 is a bit more conservative. The ProbeGT has grooved rocker panels and concealed headlights, the MX-6 GT blisteredrear fenders and a deck lid spoiler.

The most noticeable styling difference is best appreciated inside thecars. Probe`s rear window is too slanted. You not only sacrifice rear vision, you lose valuable head room in the back seat. The MX-6 rear glass stands upstraighter and allows you to carry adults in back without cramping theirdomes. The one drawback is that the front passenger`s shoulder belt hardwarestands as a barricade to entry into the back seat. A change is needed.

Both Mazda and Ford cars share the same engines and transmissions.Standard in all but the GT is a fuel-injected, 2.2-liter 4-cylinder with threevalves per cylinder. The GT engine is turbocharged to boost horsepower to 145 from 110.

The Probe GT comes with 5-speed manual only until 1989. MX-6 has optional ($720) automatic. The EPA rating with manual is 21 m.p.g. city/28 m.p.g.highway; with automatic it`s 19/25.

The 2.2 turbo is quick, and, perhaps equally important, it`s quiet. Wewouldn`t expect any great power loss from optional automatic. The 5-speed issmooth. No hangups or hesitation in any gear.

With 5-speed the 0 to 60 m.p.h. claim is 7.4 seconds, top speed 131m.p.h.

Ride and handling are crisp and precise. The car responds well from thecombination of front-wheel drive and power steering, which is a speed-sensitive unit with more assist at low speeds, less the faster you go. TheMX-6 GT offers a choice of suspensions adjustable from soft to sport bypushing a dash button.

In the sport mode the suspension automatically adjusts to reduce bodyroll, dive and squat, yet remains fairly soft on smooth roads. At speeds over 50 m.p.h., the shocks automatically firm up for high-speed stability.

We suggest sport for the best performance, soft when simply cruising forlong stretches without wanting any distractions from tar marks in the roadway.In sport, you experience far less body sway or roll in tight corners.

Though a $1,400 option, we highly recommend the antilock brakes. As we`ve said countless times, getting up to 60 m.p.h. is only half the fun, gettingback to 0 m.p.h. is the real trick. With antilock you do, in a straight line, regardless of road surface.

The price spread may be the hangup on the MX-6. The DX starts at $11,099versus $10,660 on the Probe GL. The MX-6 LX starts at $12,999 versus $11,644on the Probe LX, while the MX-6 GT turbo starts at $15,099 versus $13,794 onthe Probe.

Since Probe is going out the door at full pop plus a premium, the MX-6price spread may not be so high after all.