Hi Guys

This is my first post, I have become the proud owner of an 1.8 Audi A3, and chuffed to say the least, loved Audi's my entire life and finally have one. Granted its an older one but im eyeing up a new A4 at some point in the future, probably years off yet as my salary wouldnt quite cover it just yet lol

Anyway, quick question and probably silly - I like to think im ok with repairing straight forward things in cars, ask me about the engine and then you lose me :P

However, my wing mirror (driver side) has a hairline crack along it, it isnt split in half or anything and you cant feel it if that makes sense? But obviously i need to replace it, im assuming its an MOT fail if its not done?

I bought the adhesive glass however due to severe rain havent been able to fix it myself. Im just looking for some guidance on fixing it - what prep work needs done and once thats done is it a case of just sticking it to the existing mirror? As i've said, although there is a crack right along the mirror, it cant actually be felt.

Hope my query makes sense! I had a search and couldnt find another post answering this directly so forgive me if there actually is.