My guess is, you don't want to make the top any higher than your CRV.. (or wider). That would load down the trailer like crazy..
I think it should be the same height & width as the CRV or smaller.
And, the nose should be as close to the CRV as possible (and still allow turning).
It seems like you would want the trailer to
'draft' on the CRV.
And not stick anything out into the wind streaming by.
The tail end of the trailer should be a boat tail.
It doesn't have come to a point, but can be a truncated boat tail..
I'm just shooting in the dark here.. The more trailers I look at on the web, the more I like the old Airstream design.. They were pretty easy to pull..