But this McDonald's is located at 140, Avenue Champs Élysées! It is arguably the one at the most prestigious location in the whole France. This is just one block away from the Arc de Triomphe, on Paris's most famous avenue. I have eaten there myself: http://goo.gl/maps/ofMu
I highly doubt it is a front for a shady business. It would be like claiming the Apple store next to Central Park, New York City, is a front...