I've been helping a few people with CARS lately, and after working through their mistakes together, I kept seeing similar patterns come up that affect them being able to break through a plateau: indecisiveness. Specifically, second-guessing and switching answers.
I know the advice to "trust your first instinct" gets repeated a lot in this subreddit, but it tends to be true. However, I think people struggle with that because occasionally, by switching would've gotten the question right. Here's the thing though: if sticking with your first choice is right 8/10 times, that 2/10 shouldn't be driving your strategy.
When you're torn between two answers, it's usually because your first choice didn't feel airtight, so you started trying to justify the second one. Stop doing that. Instead, ask yourself one question - is there anything in the passage that directly contradicts my first choice? If the answer is no, go with it and move on. If you have to reach to justify an answer choice, then it's probably wrong.
For questions where nothing feels obviously right, maybe flip your approach. Instead of asking "which answer could be correct?", ask "which answers are definitely wrong?" Eliminate anything that has no basis in the passage. If one option is left that you can't confidently rule out, that's probably your answer. Even if it doesn't feel perfect.
Lastly, if a question references something specific from the passage, go back and find it. Don't rely on memory. This is where knowing the rough structure of the passage pays off, so you can locate things quickly without rereading everything.
This matters especially when answer choices include details you vaguely remember from the passage. First make sure the choice actually answers the question, then read it carefully. The MCAT will sometimes slip in a single word that makes it wrong. Ex. The passage mentions "the elite" and later references their time on a farm, an answer choice that says "urban elite" is incorrect.
Hope this helps someone and good luck!