I agree with has been said above. I think the number one thing is practice and be confident. I went from 123 to 128 in CARS. I did as many questions as I can get my hands on. Was doing 12-15 passages a day for a good 3 weeks before the exam. I think there is so many CARS practice out there, the old books works as well. Confidence was key for me, I think the practice helped me become more confident. However, I didnt practice much on any science sessions that summer when I re-did mcat. If you are struggling with analysis of the text, taking a course is good. JW is a nice resource to check out.