I use my HOTAS yaw as steering, and my mouse as turret control. I can indeed look around in the turret, and use the front bumper grill as a reference (as well as the "turret pointing thisaway" display) to steer the rover how I want it... but its confusing- and more than a little nauseating actually driving around bumpy ground in that first person view (oddly the canopy "shift" seen in ship cockpit and rover helps a lot for me)
But I don't think you can sit in drivers seat and control turret- its automated (like gimbaled guns)- auto aiming at what you've locked onto.