Hope this helps. I don't know exactly how the surfaces work out in 3D but it should work fine.
I also added rear wheel skirts and small front skirts. You shouldn't have a clearance issue up front if you put them down only to the top of the tire.
Skirts, kammback, some taped gaps for good measure. Consider extending the front skirts to cover the wheelgap in front of the tire as well, but make sure you have clearance when steering. There's a Scion xA on here with a well-executed version of these.
I made the kammback clear because I'm kinda lazy but using some sort of angle brackets or other structural reinforcement is highly recommended. They can usually be slipped into existing bolt holes inside the edge of the hatch.
That's pretty close to what I'd do...