Will regulators end up requiring a minimum head to windshield header distance?
 

While I admit I drive a bit too close to the steering wheel, modern cars feel so cramped inside.
I'm having a hard time feeling roomy in most non-SUV cars.
Even if this is aerodynamically helpful most people wouldn't tradeoff comfort for aero.
I also guess this windshield header closeness might be dangerous in a crash.

Would regulators step up and mandate a minimum head to windshield header distance?
Of course it will depend on how far back you move the seat so maybe it will be related to the steering wheel position?

If a windshield needs to be very inclined for aero that's ok but why can't automakers move the windshield forward?
I guess the reason is not aerodynamically or structurally related. I guess its based on styling as cars with short hoods tend to look feeble as compared to long hoods.

Do we really need more regulation. I do understand what your are talking about. The Grand Prix has very little head room (I'm 5' 9") and the windshield ends above the steering wheel. But my take on it is the drivers seat is too high. Looking straight forward uses the upper 1/3 of the glass.This is of course a personal preference having driven many sports cars with the seat very close to the floor.

I also drive in what is considered less than optimal seat location, too far back and with a slight recline.

I agree most of it is about styling and compromise.

In light of the "new" 1/4-offset NHTSA "crash" test requirements, the answer will probably be "yes" more mandated regulations are (continually) forthcoming.

windshield header
 

The NHTSA has some stringent regulations for automakers which deal with pedestrian safety if struck by an automobile and also roof strength/rollover standards.
*The hood cannot collapse enough so as to expose the pedestrian to rigid structures underneath the hood.The windshield base/cowl must be able to deform in a pedestrian impact.
*The steep windshield is actually beneficial in an impact,but aggravates A-Pillar strength as well as ingress/egress issues.
*Occupant restraints and airbags are designed to limit front seat occupant incursions into the header.
*GM was attacked by consumers for their Cd 0.30 Pontiac Trans Sport type minivan which possessed a greenhouse positioned far from the occupants head.They've cast other pearls before swine and were summarily punished by the mindless automatons.
*It's funny that some of the richest men in the USA will crowd into the cramped low-roof cabin of a business jet for their commutes.
*It's quite a juggling act,building cars for sale in the USA.

I try to mitigate this by lowering the seat (power seats) as much as possible.