I believe a lot of the UPS vans are based on off the shelf step vans, i.e. https://workhorse.com/stepvans https://workhorse.com/stepvans. They may have some cus

I believe a lot of the UPS vans are based on off the shelf step vans, i.e. https://workhorse.com/stepvans https://workhorse.com/stepvans. They may have some customizations, but appear to be pretty standard.