Have to say that wasn't our experience.  We went a couple of years back because we were looking for a new car and while we had agreed on the basics (SUV, AWD/4WD, relatively small, upscale) we didn't have a firm idea of make or model.

In any case, we did sit in a number of cars that fit the basic mold and managed to eliminate most of them immediately.  Matters of "fit" (my wife is tiny and if we couldn't adjust the seat to an appropriate position for her the car was off the list), finish - I was surprised at the cheap feel of a coupld of the offerings from upscale manufacturers, and so forth.  As for the ones that were left we found the company reps to be knowledgeable and we left having narrowed the selection down to two possibles.  So it was off to dealers for test drives and pricing (Car Cost Canada helped on that front).

Absent the auto show we'd have spent days trekking from dealer to dealer to even begin to narrow things down to the extent we did in that one afternoon.