The other thing that might be worth noting, is that USMLE accredited US allopathic medical schools come in 3 flavors... good, better, and best. If you get into even one of them, you're in pretty good shape. From what I can tell, the rank of your school doesn't really matter as much as where you end up doing your reisdency and what your dean's letter reads.
It's hard to get into medical school at all, and there's no formula for consistenly getting into the top ones. Having high grades and MCATS will help, but I'm sure the interview and other intangible become more important as you reach the phase where everyone left in the applicant pool has similar credentials. I uodn't get fixated on the top 20 schools so much. Different schools are better at different things, but it's hard to differentiate a lot of them otherwise in overall quality.