Ditto on just taking it to the store, you might walk away with a new laptop. I dropped my ipad 2, it cracked the screen in the corner, a hairline crack. I explained to the tech that I dropped it and was cringing to hear the repair costs but he asks me how much memory it had and which 3gs it had then walks to the back and brings out a new one and hands it to me. He then explained that he could tell it was an accident instead of negligence due to the nature of the crack hence the no-hassle replacement. I did not have Applecare on the Ipad. He said that if it happened again that they couldn't replace it a second time - understandable.
Therefore the fact that you have a hairline crack may resonate properly with the techs and they'll see you aren't trying anything funny on them and they'll just as likely help you out in an unexpected fashion - all you got to do is go and ask.
Therefore the fact that you have a hairline crack may resonate properly with the techs and they'll see you aren't trying anything funny on them and they'll just as likely help you out in an unexpected fashion - all you got to do is go and ask.