[Angel And The Wolf]

I'd start with a Prius, and boat tail it. I've only had mine up to 85, but it was surprisingly smooth at that speed.
Here's a video of a 2007 at 108 MPH

https://www.youtube.com/watch?v=mzFK56epaHI

and here's a prius at 195 KPH

https://www.youtube.com/watch?v=Erzh7Qzq4bk