Carving a space for a roof vent

I bought my first van and don’t want to do any of the windows. It’s a Dodge Promaster high roof. I am on a really tight budget but the most important thing is the roof vent. Anyone know of any resources, or where to start?

Put it as far away from opening windows or vents as possible. That way you’ll get good air flow throughout the van. Most vents use a 14x14" opening. When you cut the hole, be sure it’s not through any structural body ribs or you might compromise the body. Should be plain flat sheetmetal. Other than that, follow the instructions that come with it and power it from a house battery, not the starting battery.