Feedback taken. In the mean time you can start a private match → go to game options → Advanced and switch the Division to whichever division you want to look at. From there you can go into buy car or wherever. But a car list seems helpful and took the note.
Edit* I should answer the Rental question. The reason they don’t show up for some leagues is that we bump the class in some cases to make it more interesting and a little twist from career. Since rentals can’t be upgraded, there won’t be any valid ones in the list that are “B” class. Hope that helps.