Mine has one grill in a metal frame which when fitted stands vertically behind the seats and is the main wind deflector. In addition there ia a piece of strong gauze (nylon?) which stretces out horizontally over the rear seat backs and velcro's to the carpet behind the seat backs (or in my case is fastened more positively with elasticated bands to the in-built corner fastening rings that the tonneau/hood cover also fastens to. The photos on E Bay show this fairly well.
http://cgi.ebay.co.uk/ws/eBayISAPI.d...m=280364356856