I did something similar with my new 4Runner. Basically took the Toyota Hot on the Lot deal web offer from one dealer, and shopped it at another dealer. The first dealer had a sweet deal on a Black V8 SR5, but I really wanted the V6 for my daily commuter. Walked onto the second lot, and as soon as the sales person descended on me, flash the offer in his face and asked if he could beat it on an identical V6. Saved some cash and got the ride I wanted.
It probably helped that I did this on the 2nd to last day of April, late in the evening....