Place steak into a plastic bag and pour in marinade. Stow in fridge for 2-8 hours.
Travis's tips on grilling: (It seems most people have their preferred way of grilling a "perfect" steak, and it varies greatly depending on your grill and cut of meat!) (For a large piece of meat like this tri-tip) Heat the grill on medium high and cook for about 10 minutes on one side, then 8 on the other, closing the lid between flips. Place steak on the top rack of the grill and reduce heat to medium. Close lid and cook for an additional 20 minutes.