NOT for eco-warriors or shy, retiring types, the Mexican-built Suburban is as unsubtle as you can get. Massive construction, a beefy motor and room to sprawl, it is American excess at its best. Or worst. Don't ask about the fuel consumption, for instance. Its relative lack of refinement and wayward, barge-like driving characteristics make it ideal for those who tow big boats and do not live in the city. The interior is fairly tacky and the seats are not exactly the most inviting chairs in the world.