The 42 runs up I-Drive towards Prime Outlets (ex-Belz) and does a right, goes over the Florida Turnpike and turns into an industrial estate. As it comes out that estate, it crosses some gateless level crossings and turns left on to a main road - Sand Lake Road - OBT is (from memory) the second major crossroads junction with lights, you'll know when you've gone too far because the bus will have turned right on to OBT! CompUSA is not obvious from Sand Lake Road, you have walk back up OBT a couple of hundred yards or so and it's on the left.