Set Illustrator's raster effects to 300 ppi, and give placed images an effective resolution of roughly 720-1,000 ppi at 1:10 scale — which works out to the 72-100 ppi large-format printing actually needs at final size. A 150 ppi stock photo that looks fine on the artboard prints at 15 ppi on the van. File setup guide: wraptor.io/blog/how-to-design-a-vehicle-wrap-in-illustrator.