I recently got a pair of OEM Black Jack mirror caps for my 2019 Countryman and the hole for the courtesy lamp is not cut out. There is a stub out for the hole on the inside of the cap to start the cutting.

What is the best way to make the hole without damaging or chewing up the cover?

 

A small piece of tape, and a careful drill bit hole?

 

I was thinking that too, but the hole is not round. More oval shaped and wanted to see if others had a tried method for making the hole,

Anyways, I tackled it quite easily with a 1/4 drill bit to start the hole and then a round file to make the oval shape and smooth the edges.

Here is the hole I made in the cover.



And the finished product installed!

 

Great! Love the round file idea, too! Nice job.