I have a 2001 Ford Econoline that I turned into a simple camper. I bought two 100sq foot boxes, and had enough left over to use for areas I hadn’t planned on insulating! I did use a combination of wool and rigid foam for larger flat areas (like the windows and in the doors), and used spray glue to adhere lots of wool to cover all of the non flat metal surfaces.
This van has a LOT of metal nooks and crannies, so ripping the wool panels up into smaller pieces to shove into every area was super useful.
If you don’t like the smell of sheep’s wool you may want to reconsider this product, but I love the smell and am really happy with this purchase.