Have found same problem with filter from opie oils. After Bloodied knuckles and much swearing I realised that It's simply too long, and it wont fit if you have a mocal (and probaly any other) sandwich plate/oil cooler set up. Because the sandwich plate shortens the gap by however much it measures.
I bought the listed GTIR filter made by ADL or Blue Print and stood it on a table side by side with the Opie one, and and the old, used filter off the car which may have been nissan. Wot y know! The opie one was a good bit longer, some 10mm than either the others. The ADL filter fitted with difficulty, but at least it fitted!