CarMax, the nation's largest used car dealer, is looking to hire more than 50 sales associates, technicians, office staff and others at its new Pleasanton location set to open May 18. The site will be the chain's first in the Bay Area. Pamela Ott, Pleasanton's director of economic development, says CarMax, to be located at 2750 Stoneridge Drive near the Livermore outlet mall, will be a boon to the community -- especially job seekers.