Hi!
I don't think Kaplan's resources are all that good for the CARS. I took all their available verbal content when I was studying for the MCAT, and while it probably helped some, there just too many better resources for you to use (EK101, TPR, obviously all the AAMC stuff, etc.). I'd try moving on to one of these more reputable resources.
- You say that you usually run out of time by the last passage. I cannot recommend this enough, you have to get your timing down to do well on the CARS. I'd try to do more passages and spend less time (if any time at all at this point) reviewing the test. You're hovering at around 50% correct. I bet you're having to rush through the last two or three passages which is having a major impact on your score. Instead of spending two hours reviewing three or four CARS passages, you'd be much better off taking 12 more CARS passages.
- You've got to read the whole passage. Don't skim. Read slowly and for detail. The problem is not that you're spending too much time reading the passage, rather you're going back to the passage a ton when you're answering the questions. Until you have your timing down, I recommend you read the passage once and then FORCE yourself NOT to look back at the passage. Your timing problems will resolve themselves nearly instantly and while your score might initially go down slightly, you can slowly allow yourself little peaks back to the passage, titrating the amount of times you allow yourself to go back with making sure you finish on time.
- Don't triage. If you want a decent score on the CARS, you've got to do all of the passages. Do them in order. Don't waste time trying to figure out "is this a hard passage or an easy one." Often hard passages will have easy questions and easy passages will have hard questions. It's impossible to know by just skimming the passage. You'll waste time asking yourself "now or later" and won't be able to focus on what you're reading.
My recommendations would be to work on your timing and keep doing a lot of passages. I think you can probably expect to see a 8 to 10 question bump in your score once you get your timing down. Then you can focus on implementing a few new techniques.
Best of luck!