I recently came across the term "Dirty Dr. Pepper." A little research revealed that it is a drink created by a soda shop somewhere in Utah. It sounded like the perfect non-alcoholic drink to serve at a Labor Day get-together.
All the recipes I found varied in terms of quantity and while most recipes called for coconut syrup, some suggested vanilla or even fruit flavors. I happened to have a bottle of vanilla syrup on hand so I went with that. My glass only held a half a can of soda so if you are doctoring (no pun intended) a whole can, double the quantities. Of course they are fluid--use less or more to taste.