Decided to sort the rear speakers out as the standard 4" Subaru items are the cheapest, worse quality speakers I have ever seen.
Had been given these second hand 16cm speakers a while ago so thought id give them a try.
Was pretty obvious they were never going to fit in the standard openings so I cut the holes to size with a dremel and gave it a quick paint to stop any rust.
Door cards fitted back on fine and definitely sounds a lot better.