I'm quite new here, but I have a similar problem with my lid on the same model of MB...
My lid seems to be crooked, you can tell when it's shut, it's off a millimeter or so. So, since mine is still under warranty, I took it to my local Apple store and the "Genius" told me it is just a cosmetic issue and not to worry about it. However, they may consider a crack more serious 😕
I was hoping they would give me store credit, instead of exchanging it, (since this model is discontinued) for the original price of $999, but that was wishful thinking... 😎