Yipper... I'm a sucker for engines, compartments of any kind and any door/hatch that can be left open!
I usually decide at a later stage what is going to be left open, especially if there are going to be figures interacting with a vehicle.
So I don't worry during the build, just go at it and paint everything, enjoying the process.
Sometimes I find really good photo references, and get carried away with painting and/or customizing areas that could have been left untouched, and they turn out to be the best feature!