Did Factory Undercoat the Fuel Tanks?

I know the Mark Harmon haters will pile onto this, but here goes. I was watching Graveyard cars a while back, and Mark talked about this. According to him, the tank did not get sprayed.

On non-undercoating optioned cars, it did not get sprayed. Did he specifically say on undercoating optioned cars?

I’m surprised Tony D told him to say that.... cause most all the info come from him.