I've got a 3 year old Macbook Pro (Retina, 13-inch, Late 2012) model, and it's had a few graphic glitches in the past, but right now, it's have a pretty nasty glitch: I haven't rebooted or anything yet to see if that will make it go away, because I'm not sure if I should really be concerned about this or not. Is this a bad sign of things to come? it kind of reminds of maybe of an issue I've seen before (maybe on macrumors even?), but I don't recall whatever happened with it. I don't have applecare, so am I screwed if this gets worse? If I take it in to the apple store to have them look at it, does it have to be displaying the glitch for them to know if the graphics card is bad? Or do they have ways to test it?