I do these often. So much that in my last round (every store in my rural area) the manager said "Hey I remember you. Let's do this." We both just laughed. These are easy and fast and since the original post the audit has been streamlined a bit.

I love it!

You can print the letter of Authorization from two places.

1. Your email when you are assigned the shop. The document will be a PDF.
2. After clicking on the shop in your assigned shop area it near the top with the location information.