Passenger Side Arch Liner

[hopgop1]

Not the usual arch liner post, I've had a brand new set sat around for a while, so today while I had the car up in the air I figured I'd swap the passenger side over. I've removed what was left of the old liner, but I cannot figure out how to get the new one in? Anyone got any idea what I'm doing wrong?
The extra flap that goes on the engine bay side doesn't seem to fit in anywhere.

Old vs new:

The flappy bit that doesn't seem to go anywhere:

This is as close as I can get to fitting it and it's definitely not right:

 

[hopgop1]

Never mind I was being retarded, the flappy bit was bent the wrong way around on mine, presumably from being stored for a while. Bent the other way and now fitted properly!

 

[Louis]

Did @Chrisgti6 bend this flap too?

 

[hopgop1]

Did @Chrisgti6 bend this flap too?

Nothing wrong with bending a few flaps