I went last year with my car and it was great, had over four hundred cars there, GM had basically there whole line up there for you to see and sit in. Also they have tours of the plant, which was great to see and imformative.
They have vendors there selling different stuff as well.
This year the Corvette ZR1 is going to be there:dro:, and hopefully the camaro to. (fingers crossed)
If you are off this friday, you should defitently come to St.Catharines