Maybe this is it. The limit. The point where shoppers glance behind at the 200-plus spread of sedans, wagons, and minivans they deemed inadequate transportation, then glance ahead at the Suburban and Excursion, and finally feel content to say "enough." An Excursion's great for hauling home an entire Costco, but sometimes, Safeway will do. Why put up with an Excursion's atrocious 10 MPG when the Expedition can manage 12? Whatever the reasons, regular full-size SUVs, as a class, outsell their larger-than-life counterparts and have been the ones to attract competition in recent years.