i've heard of residency directors asking for your MCAT scores, but i think it's a curiosity thing and doubt they factor highly into any decisions. i've never heard of anyone asking for your COLLEGE grades, because how would your grades in college speak to your ability to be a competent doctor? even in med school, your clinical rotation marks (the ones that speak of your competency in the hospital), along with your board scores, matter more than your course grades when looking for a residency. no med school has asked for my high school grades because at this point in life, they're totally irrelevant. i've been out of college for several years as it is, so by the time i go looking for residencies, my college grades will be almost 10 years old.
you're all worrying too much. while it depends on the particular med school, just don't get any grades below a C and you'll be fine for the vast majority of schools out there. 🙂