Kona electric = 0.29 Cd. Unusual to get an electric car on my local dusty roads.
There's a mixture of dust deposited by low aero pressures and heavier mud flicked up by wheels. Looks to me like there is some separation ahead of the flared rear wheel arch. Very good attachment, though, behind the rear wheel as far as the separation edge - except right down the bottom.
The back looks very good. Top separation edge (roof extension) working perfectly, side of hatch extensions (complete with vortex generators) again working well, hard to tell how well the upper light and immediately below it is working, and then lower sep edge again working well.
Just by observing their cars, I do think Hyundai / Kia are right at the leading edge of this stuff - but no tech papers as far as I know.