The DPi section of Mariantic has some good info if you haven't been on there in a while:
http://www.mariantic.co.uk/lmp/DPI1.asp
Oreca thinks they will have a DPi customer for 2018, and possibly another for 2019.
But what i really liked were the side by side comparisons from Pan_Nullo. It really allows you to see what the differences are (or aren't) between the base P2 and the DPi bodywork of Mazda, Caddy, and Nissan.