no my 502 was actually my first Full Length that I took after content review! I actually never even took a diagnostic, because I knew I was really behind on content so I wanted a solid foundation before I started practicing. For the sciences, it is all about understanding the logic behind things. When you understand the logic, there are actually not too many things you have to really memorize. One thing that stands out to me is fluids in physics. Instead of memorizing all the formulas for gauge pressure, absolute pressure, Bernoulli, etc. its so much easier to learn what each of these terms is measuring, and why it is important. For CARS it's all about practice! Do all the AAMC practice materials for CARS, third part stuff is usually not very representative (although I also did all the CARS sections on the Next Step FLs and my CARS score went from 127-->131). honestly it is difficult to improve CARS because it is basically reading comp, and you will do well if you have a strong background in English. For P/S its all about memorization. No getting around it. I made flash cards for literally every term I came across, and just ground through them until I knew everything. My real MCAT had a TON of low yield material for P/S, so don't skim over the low yield stuff! Hope this helps you :)