Did mine a few months ago, its severely underrated the difference it makes.
Few tips, get it everywhere in the door(I used 8 A4 sheets per door). I mean everywhere, I pushed mine nearly to the top of the door on the exterior and interior panel.
Towards to front there's a curved piece of the door, this made a big difference to mine.
I half assed the drives door, but spent a good hour doing the passenger, its very noticeable.
When you tackle the other 3, get yourself a narrow paint roller, works wonders and you'll still have your fingers.