Marinade your rib roast for 1 hour (30 min. in refrigerator and 30 min. at room temp.)
Heat Barbecue to medium high heat. Sear rib roast for 3 minutes on each side. Remove roast from barbecue. Turn down heat to an indirect heat (turn one side of grill to low and keep other side of grill on medium high)
Wrap rib roast in aluminum foil and place on low temp. side of grill. Shut lid on grill and let it cook to the desired doneness.
Let roast sit for 10 min. Slice thin against the grain.