blow down tubes ARE NECESSARY for all types of racing, not just test and tune but real racing as well, the tube has to be mounted to the botle and VENTED OUTSIDE the vehicle. so yes you will have to drill holes. the bottle must be mounted in the rear portion of the vehicle and the top of the bottle must be inline with the intake tract. they will not allow it any other way. all those people with bottles mounted sideways and crap to make it look cool are never going to be allowed to race their cars legally cause it is actually a hazard to the system itself, bottles need to be mounted at a certain angle (predesignated) or you are chancing serious harm to you and your car.