Dear Rob K. thank you for taking the time to read the article!
We have tried to answer your question below, hope it helps.
If it is a horizontal navigation placed at the top, the menu items will not be hidden and shown upfront. If it is a vertical navigation aligned to the left and the menu collapses (I would not recommend collapsing everything in a hamburger menu, at least have the icons shown in a compressed version of the navigation on the left) then alerts can be shown on each icon if there are things going wrong in respective sections.
For drill down navigation, it is my recommendation that at max the nav can drill down one additional level. So as be your example: Car Manufacturer/Make -> Model. However, I would not recommend this if there are more than 5–6 items in the drill down menu (if the car company has more than 5/6 models). This is because the navigation in a dashboard should be used to take the user between larger sections and drill downs related to product can happen through the use of filters.
The top left area we mentioned is the one below the navigation so the logo would still be in the same place.