Bad luck Jackso11, my husband accidently caught our driver side mirror coming out of our garage. It also cracked the plastic surround which has to be replaced as a whole package. Ford quoted around £200 to replace it and although I trawled loads of websites, I couldn't get it for much cheaper. However, if it is just the back panel, it is about £35 and easy to do yourself so fingers crossed.
Luckily ours was able to be pushed together and glued with only a miniscule crack but it is so frustrating just to know it is there. will probably get it done when it gets its first service.