You ever go to the North American International Auto Show in Detroit? I've been the last two years.
Technically, the NAIAS is smaller in square footage than the Toronto International Auto Show, but the displays are much nicer. It seems they spend far more money on the displays there, and it shows.
Granted, you generally do not see anything at NAIAS that you would not see at TIAS, but it is quite an experience. That said, last year they had the Porshe Carerra GT, and I don't recall seeing that in Toronto. That Porsche alone was worth the trip and price of admission...
Yes, it is four hours each way from Toronto, but I personally like driving, especially road trips, and I am lucky that I go with friends and we end up just talking all the way, both ways, and having fun. The trip feels like nothing.
Try it! You'll like it!