Sorry but. I think there is a walking service, this is a copy-paste from the webpage:
http://www.canadainternational.gc.ca/detroit/visas
If you applied for permanent residence in Canada and you have received a notification from our office, the Case Processing Pilot Office in Ottawa or the Canadian Consulate General in Buffalo requesting you to submit your passport(s) to our office you may do so in person on Tuesdays and Thursdays between 8:30 – 11:00 am. Your passport(s) may be returned to you the same day. You must bring the notification with you.