Two years ago we actually paid to see a generic Hyundai Elantra or Toyota Corolla - because we were actually car shopping, and going to a show saved us a lot of time rather than criss-crossing Toronto in search of dealerships that actually have all the models on display. The show was crowded as is, and I believe it would be even more so without some sort of an entry fee filter. 

 Same goes for bridal shows, or stamp shows, or whatever other show one wants to visit: the paid admission model is very typical in North America, but such shows are well worth the fee for gas savings alone.