I agree with the post above. An 87% is quite solid - its indicative that you are able to understand the passages, have a good grasp on concepts, and know the details quite well. A 96% on the sample test is also a good indicator. That being said, when you're at the high end of the score range, missing an additional question or two per section can have a big impact on your subscore. Stay focused, make sure you thoroughly review all AAMC questions, particularly with CARS, so you can pick up the subtle things they do with word choice and structure of their questions. Best of luck to you.