I purchased a set of tires at Radial Tire Company, also in Silver Spring, and they referred me to Allen Automotive for an alignment. I asked for a 4-wheel alignment. Allen Automotive checked all 4 wheels, but only performed the alignment on the front 2 because the rear two were in suitable configuration. I was a first time customer, and would have willingly paid for all 4 wheels, since that is what I asked for. I'm very impressed by the integrity shown by Allen Automotive, and will return to them for additional service needs.