Glad you had a nice trip! Toronto is a great city, traffic notwithstanding.
You probably got a few stares with the SD as they just don't last up here...they rust away. Not many older examples driving around in good condition. The odd one, yes, but fewer each day. Even the relatively new W210s have gone...
I've travelled to many US cities and would agree that Toronto is pretty similar. Montreal less so, and Québec City is even more foreign. It's truly a gorgeous city, very European. It's just so far from anywhere...
As for driving 100 Km/h on the 401 in Toronto...the Toronto police once had a blitz on in the summer for drivers going too slow in the left lane. They stated, on TV, that drivers doing less than 115 Km/h in the left lane would be ticketed for impeding traffic. Limit is 100. Most drive about 120-140 Km/h on the 401 through Toronto. Go figure, only in Canada.
The really crazy thing about Toronto is the film/tv industry. Seems like a new show or movie is being filmed there every day. Hollywood North...