isocyanate boards.
dealing with insulation stuff building up a van. Add in a couple decades in the OEM side of the auto industry.
The thermal insulation is different than the acoustic insulation, but there is overlap. The dense closed cell foam is best for thermal. Mediocre for sound. Even sounds falls into different categories. Mass type materials (dynamat) is good when the material itself is generating the sound. The classic trade show demo is a pair of cymbals where they are both hit with a drumstick. One will ring and the other will thud. But they don't do much for reflected sounds. Reflected sounds are like an echo where the sounds just reflects off of something solid. For that a looser fiber does better. Think of a room that has hard floors and one that has carpet. The fibers of the carpet absorb the sound. Thinsulate works good for that.
The mix if stuff I used is truely a mix. The thickest asphalt (dynamat style) sheets and applied small pieces to the larger panels that ring. Don't have to cover 100%. Have even heard that over-covering is worse. Selective panels that ring like a cymbal got a half sheet of paper size applied. Rock wool went in were I had access and depth. Thinner areas (and the roof) got thinsulate. Floor was a buildup of isocyanate that is only half inch thick and is really impressive for how thin it is. But only comes in flat sheets, so hard to work with in a curved space. The floor was one of the last places to get worked on. Now that I have worked with it, and lived with it, I would liked to have more iso board for thermal insulation.
With that said, the biggest issue is the glass. Sun just shoots right through and heats stuff up. And cold passes right through as well. When parked I use insulated, reflective window covers. They make a huge difference over the windows. There isn't much you can do about using single pane glass. Reflective tints help, but don't do what simple insulation can do. With the glass to volume ratio a Bronco has, it is going to be a fight.
Going really extreme. As in there are so many other issues you will never see the benefits of it. They do make acoustic glass now. It is used in autos. It is a variant of laminated safety glass. The inner layer is different and has acoustic absorbing properties. But you would need to so much other stuff quited up before you would see a benifit to this stuff. It would need to be custom made, but with flat glass that isn't that big of a deal. Finding it would be the harder part. You would need to be looking at specialty glass shops to even find it.
