this is a small image from a previous version of US packaging items for McDonalds, featuring an intriguing script, and I challenge myself into hoping it's not custom lettering. Any chance such a font might be out ther somewhere?
Typophile
Script from old US packaging items for McDonalds
My vote is custom, as most franchise logos are, and especially since the "d" attaches to the "s" regardless of the apostrophe between them.. but the first thing that came to my mind was El Ranchero from FontDiner.
Captured from web.archive.org on 19 Oct 2013. view this capture