From what I gather, some A&W locations use their annual "Cruisin' To End MS" day (which is tonight: August 21) as a classic car event as well.
Can't tell which A&W locations are doing that; wish they had a list.
Text from the link below: More than 800 A&W restaurants across the country will host Cruisin’ to End MS events, which may include Cruisin’ the Dub® classic car and hot rod gatherings, retro music, car hop service, A&W Root Beer® chugging contests, and visits from the Great A&W Root Bear
I might take the kids for a root beer at the Victoria St. (closest to my house) or Westmount location in Kitchener tonight just to see if anything's happening...
UPDATE: well, that was a bust. Nothing happening at either location.