Your back will love you!
I did similar, but found there was a lot of reflection when at the same angle or the dash. I needed to tip the gauges forward.
Thought the multi color e ink was going to work but it’s a slow update in red. But if ai stick with black it’s about 1/2 second screen update.I have 3 Pis sitting around so I am interested in your progress. Please let me know how that works out.