[Alan in AZ]

Well - it just bolts on - it should have studs on it if its a factory wing and you need dome nuts washers and and a shim that levels up the folded underside sheetmetal of the hatch skin. You won't have these shims and likely won't find them but could make one. I'd use a strip af aluminum the same thickness as the hatch skin and cut to just over the length of the 2 studs and drill mounting holes overlapping its edge - so it levels out the underside of the hatch - then I'd use a washer over the top of this. The S4+ hatches have a recessed area to allow for the bolt heads - not sure how well this will work with the OB hatches you'll have to do trial & error. You will have to drill the hatch - make up a template to make sure you get the right spacing & locations. On the paint side a thin rubber or plastic gasket will help protect the paint .

Alan