Recently purchased GP1 #0092 with 93K on the clock and the underhood liner was looking sad. Thought about purchasing a new one but thought I'd try cleaning it up first. I purchased a sack of 30 #51481915964 plastic rivets (you only need 13 ea. but MINI sells them 30 in a pack). Take off the two nuts holding the bottom of the hood scoop frame with an 8mm socket, then remove the plastic rivets to free up the liner. I vacuumed both sides, then lightly scrubbed the front side with a damp sponge. I let it dry overnight, then touched up a few minor abrasions with black liquid shoe polish and let it dry. Installation was easy. I started by putting in rivets at the top and worked my way down, tucking the edges back under the hood scoop frame. I was amazed at the results!

 

Were you able to get any before/after pics? I'd love to just replace mine, but never thought of actually cleaning it. This job sits right next to replacing the failing headliner that I just keep tacking back into place with glue, it's work that's needed but not at all necessary to operate the vehicle. I'm getting lazy in my old age.

 

Here's the "after":

 

Here's the "before":