I can't imagine a store that carried Trek and Specialized. Where I live, the stores that carry those brands are driven by those brands, and evrything else is very minor and shived in the background. If one shop tried to carry both, I would imagine things getting ugly quick.
Example: I went to LBS#2, which lists several different brands and (at the time) was the only store to carry Cannondale. I knew that Cannondale and Trek made the two biggest production frames, so I went to test ride a big frame. They told me that they didn't have a Cannondale in my size, and when I asked when they would, they told me that they were phasing out Cannondale because it didn't have as many options for fit as Specialized. I see now that was a load of crap. Anyway, six months later LBS #1 was carrying Cannondale instead, but I already had bought a Trek off the 'bay. Never did get to test ride a Cannondale...