Bakkie conversions were popular with the old Mercs and I remember our old Volvo was converted to a Bakkie by the new owner when my dad sold it in the 80s.
I have seen an E38 beautifully done in Pretoria, owned by one of the guys at Computer Corporation in the M3 E46 yellow. That was a few years back.
Personally, BMW for me is a car, not a commercial vehicle!
But if you have the time and resources to play with an old beater and build one like this, why not?!
Looks like a lot of fun! The project itself and driving it!
Nicely done!