Adrian Gaylard (head of Jaguar Land Rover aero) has released his PhD thesis.
http://wrap.warwick.ac.uk/143065/1/W...ylard_2019.pdf
It's a really excellent thesis, especially (for me) in:
(a) describing wake behaviour of squareback vehicles via really clear graphics
(b) correlating that behaviour with what can be observed on different squareback vehicles simply by looking at dirt deposition patterns.
It's a pretty intense read but key lessons (at least for me) can be gained largely by looking at the 3D graphics (eg page 83).