Richard - the OEM one will cool the motor just fine. Since the car is making less than OEM power, I can't see how there would be an issue.
The OEM one is legal as installed from the factory. If you modify it to angle more forward, I would have to ask why.
If you install a non-OEM one, I would guess the face of it would be subject to the "OEM location +/- 1 inch". I would also assume it should not be angled at all.
Your allowed to extend the OEM one left to right and down.

To me the rule is pretty clear......