VA Nationals seating question

[Mustang]

I'm looking at seats at VMP for the national, it appears there are three sections of reserved seats (pit A1, A, B) then two sections that appear to be unavailable (pit C, D). Why are these two sections unavailable?.

Thanks in advance!

 

[NitroLuver]

I know there is a new structure/garage building at the finish line end of the grandstands. But I wouldn't think that would affect the middle sections of the grandstands.
I'm pretty sure all sections were open for the last race of the PDRA season.