What exact tools did you use the install the rivnuts? I'm looking to do the same as I'd rather not drill more holes into the van leading to the potential for more rust. And how did you fasten the boards to the very front of the van, behind the seats? The headliner in the cargo style end there, I think I'll need to cut into/remove a bit of it in order to access holes that can be used for a rivnut. Any advice you have would be great!