Hi,
I believe 7/7 is enough time to raise your C/P and CARS scores, but I would postpone until 7/20 just for the extra couple of weeks.
I didn't get a stellar score but I did just break the 510 plane (which I believe is your stated goal).
Here's my advice. (*****People with superior C/P and CARS please chime in!!!******)
CARS: There's no sense in trying to gauge which part of the passage is the most or least important because questions can come from anywhere. I think this section is all about timing. How quickly can you read an entire passage and generally understand its content? If you can't read the passage fully and answer all questions within a 10-minute slot, then I'd rely on AMCAS or third party passages (Kaplan, EK, Khan, etc) to just practice, practice, practice getting that timing down. Ideally during the test you should be able to read/answer a passage in an 8-12 minute window averaging 9 mins per passage. Again, the key is fast but comprehensive reading. If you're having trouble with content and question stem interpretation itself, I'd rely on the Kaplans and Berkleys of the world (sorry, I know this last piece isn't super helpful!). What also helped me psychologically is thinking of CARS (and PS) as the fun sections (cardio, if you will) where you don't have to flex the brain as much (I don't mean to be insensitive; I know some people find some sections easier than others! just my perspective).
P/S: My worst section (I blame a sleepless night the eve of my test because of nerves. Have a backup plan like melatonin or any surefire way to go to sleep. The anxiety/excitement/adrenaline the night before the test is very different from all others leading up to the test. In fact for anyone reading this I'd go as far as to say schedule an afternoon test if possible). I digress. I relied on heavy review of my undergraduate physics, gen chem, and orgo courses for the content (might as well tap into and master already-established memory patterns). The only other source I used was practice mcat exams and question packs. The physics can be boiled down to one big spreadsheet that you memorize of the formulas/concepts to know (if you need one you can message me and I'll send). Also, these passages are shorter than Bio so you should be able to read them in their entirety before answering questions (if not, practice reading speed!). There's no avoiding an obscure orgo question or coordination matrix question or low-yield material in general. But mastering high-yield/what's likely to be on the test was the theme of my study efforts.
Again, others with more experience and better scores please chime in!