On all Silver Shadow cars this sits on the rear scuttle edge of the engine compartment item UB31456 superseding to UB43421. From late Silver Shadow II, Silver Spirit and derivatives the seal ran along the rear edge and about 9” down the wing flange to aid water exclusion as per UB41267 again superseding to UB43421. In both cases on the rear scuttle, the engine compartment sound deadening can hold the seal up. When fitting a new seal please follow workshop manual instruction also making sure you lightly tap the seal down so it bottoms on the body flanges.