Place ribs in a large baking dish then pour all but 1 cup of root beer over ribs.
Sprinkle 2 tablespoons salt over ribs, then cover, and refrigerate for at least 4 hours or up to overnight, turning once if possible.
Preheat your oven to 350 degrees, then remove the ribs from the root beer and pat dry with a paper towel.
Discard root beer in the pan, and wipe the pan dry, then put the ribs back into the pan.
Add 1 cup water, and cover tightly with foil, then cook for 2 hours or until meat is nearly falling off the bone. Enjoy!
For the Root Beer Barbecue Sauce:
In a small saucepan, heat oil over medium heat.
Add garlic and onion; cook 3 to 4 minutes or until onion is soft, stirring frequently.
Add remaining ingredients (including reserved 1 cup root beer and 1/2 teaspoon salt); heat to boiling.
Reduce heat to medium-low and simmer for 15 to 20 minutes or until sauce thickens, stirring occasionally.
Just before the ribs hit the 2-hour mark in the oven, preheat the grill for indirect grilling over medium-high heat.
Put bones on the cooler side of the grill, bone side down.
Brush with some Root Beer Barbecue Sauce and cook for 10 to 15 minutes, then flip.
Brush with sauce again and cook until ribs are lightly charred and meat is falling off the bone.
Serve with any remaining sauce. Enjoy!