I believe the fighter task in leg 6 is at the Canadian Warplane Heritage Museum, in Mount Hope just south of Hamilton. I've driven past it several times, but never been in.
Also, we have speculated that this is a KOR, since Joel and Ashley were seen at the Aldershot Go Station, in transit to Union Station. Two possibilities for a leg 6 pitstop may be the RBG - the Royal Botanical Gardens or Dundurn Castle. Both are close to Aldershot.