Hi Jayson,
I agree with the guys, you shouldn't be going through drill bits that fast. I'm on my fifth drill bit and they were all still usable.
I wasn't using bar C to connect the panels together because the bar goes inward. Maybe the picture of paper templates will help. If you need more measurements let me know.
The area around steering rack is open to elements so I extended the vertical panel all the way to the floor. Look at my build thread where I show front bulkhead panel. That is my cabin seal. On the sides I'll extend the panel to meet the wheel well panel and that would seal my foot well. Of course, the cooling pipes tunnel and steering shaft will get sealed also. In next few days I will be finishing that area and I'll post some pictures, that will make it clear.
Hope that helps.
Regards,
Renato