[skyking]

I tried some of that when doing my first cardboard stuff on the beetle.
I had two hills, both of which i rolled on at a specific speed so as to avoid conflicts with traffic.
One yielded 59 MPH or so before it flattened, the other 61 MPH.
I think it needs to be slower to really see a CD change, more like high 40's or 50 tops.
What do you think?
My reasoning is, the drag is getting so high up in those speeds that a subtle change will be hard to quantify.