Would like to share my experience of obtaining Multiple-entry Canadian Tourist Visa at the Detroit consulate.
The consulate is located at the Renaissance Center in Downtown Detroit. Arrive early as there will be a lot many people. They dont care if your visa has expired as long as you have a valid I-797. Many people I found were applying for the visa to either go for US H1-B visa stamping or visiting Niagara Falls.
Arrive early, on the first floor itself they will take your application ( check all your documents) and then ask you to proceed to the 11th floor to pay. The part where they check your documents takes a little longer. Many applicants were sent back at that stage because instead of filling in the visa application and then printing it, they printed the application and then filled it with pen. Completely wrong, as it is clearly mentioned on the site. The document has a bar code at the end, hence they are trying to obtain your record (your entries in the application) with the bar-code. Doesnt make sense why would someone, print the form and then fill it pen. So please dont do that, keep two passport sized photographs.
For the list of documents if you are in the US on H1-B visa ( or work-status) you must carry -
1. Approved I-797
2. Valid I-94, if it is expired thats ok. Your extension (i-797) will have the extension of the same I-94.
3. Pay-stubs and an employment verification letter.
4. Proof of funds - i used my bank statement.
5. You might want to carry your college degree incase.
I suggest parking your car at the Greektown Casino (free parking) and then take Detroit People's movers for 50 cents one way and within 5 minutes you will be at the Renaissance Center. This way you will easily save 12-15 dollars in parking at the Renaissance Center. You can take the same train back to the GreekTown Casino for another 50cents.
After you pay the fees on the 11th floor, they will ask you to come at 2:30 PM in the afternoon and collect your passport. They will not tell you the decision then, you will know when you get your passport at 2:30PM.
These are my personal experience, and in no-way do I take responsibility of the various requirements. All the information is available at the cic website. Check it out.