Great question [MENTION=599574]canadiancow[/MENTION]. In my situation, I asked for it when I was checking in at the Concierge Office. It's at Terminal 1, where I check in at the separate entrance. Check-in 1-on-1 with the staff, I asked about the limo ride, she checked my status that I am eligible, ordered a limo ride by calling some phone number. Then, walked me thru the security check-point and guided me down to the tarmac to get the ride. I was told by the driver that you don't necessary have to check-in from Terminal 1 to get the service, if you are on a layover or interconnected flights say, from the USA and then on a connected flight to another Air Canada flight, the limo will pick you up at the area where you walked out of the plane door. I don't know how to describe that area, you walked down the stairs and then the limo will drive you to your next connected flight. (that I wouldn't know how to order one)