Black dots on my MacBook Air

Before you give up why not contact Apple and get their opinion. They'll almost certainly say nothing is wrong but you won't know anything unless they do.

I assume you didn't try to clean the case exterior with anything other than what they recommend (a damp, soft, lint-free cloth): How to clean your Apple products - Apple Support. Some common household cleaning products will corrode aluminum.

Finish being rubbed off over the years. How old is the Mac?

Well, I guess an excellent body shop might be able to paint it, but that's not really something worth even investigating.

Wear is wear, the only way to stop it is to stop rubbing on the surface. Not exactly a viable solution. So, from a practical aspect, no, not really.

It's a bit like owning a new car and getting the finish dinged the first time. Sad and irksome, but it's inevitable. Just use your Mac, get your work done and enjoy it.

Unfortunately, cosmetic issue are not warranty issues. I have no doubt you took care of the machine, that's not in question, what is in question is the thinning or damaged finish.

Cosmetic damage is always sad and disheartening, but almost 100% of the time it's not going to be warranty covered. You'd have to prove Apple materials or workmanship are at fault and for finish damage, that's pretty much impossible.

Hi,

It's a LCD dot missing. There is no way to fix it.

Looks like defective anodizing.

The surface has a "coating" of sorts, a high quality anodizing but it can still wear, or discolor, and some wear faster than others.