Well, stillsearching, I would look for a box to your upper left that says "search ecomodder.com".
Sorry.
There is a formula for the radius on the front edges, some % of the gross width. It can be a half-round on the flat front face. The rear could use a box cavity instead of a boat tail. I like Coanda nozzles.
If your handle was notsearching I'd give you the links.
Let me know if you need help.
CFD software requires super-computer level performance to give a meaningful result.