There is also, the modification under the floor structure: of “v” structures, situated underneath the seats of a Humvee. Releasing the center section of the human compartment; to strictly for explosive gas release. A removable device, for non-threatening situations.
By placing “plastic water bags” within the V structures/ and drilling the plates of those V structures with small holes: you create an hydraulic effect spread out under the Humvee floor section. Small Holes relieve the impact and release the hydraulic pressures as the V itself collapses under the pressures of a large explosion/ without greatly reducing structural integrity.
To accommodate a six passenger vehicle, by extending the cab just a bit: two individuals can face each other on each side/ behind the front seats. An appropriate shaped funnel (gas escape) in the center gives all individuals a sight line across.