We purchased a Moen wallmount faucet. We had someone install the plumbing and had the mirror cut and installed but the mirror is too thick so we can’t attach the handles or faucet. Moen customer service said they don’t sell extension units for any wallmount faucets. There has to be some type of extension that would fix this problem. Do you have any suggestions? Thanks in advance for your help.

If you Google "moen faucet stem extensions" you will find quite a few. Check against your model. Faucets.com is a source.

It is quite unusual that the trim doesn't fit. How thick is the mirror ?

If you don't find an extension, you may have to remove the mirror - or cut wall from behind - and push faucet body forward. It is not as big job as it seams.

Let me know how you solved this unfortunate problem. Back to you. Milo