Buddy seat seatbelt?

[froggy]

I've got a buddy seat to go in my bay behind the drivers seat, its a wooden box type that screws through the floor.
My question is how do i fit a seat belt to this seat to enable it to be used as an extra passenger carrying seat?
I have a 3 point static belt that i intend to fit, using the drivers top mounting for the one part, there is already a seatbelt mounting on the walkthrough part for the catch section but what do i use for the 3rd point? Would i just need to drill through the bulkhead into the wheel arch and nut and bolt it? Would this be strong enough?

P.S. I drive a converted panel van if this makes any difference

 

[Clarkson46]

As the Buddy seat faces backwards why do you need a seat belt at all. Just drilling a hole is not strong enough it will need some sort of reinforcing plate to support the anchorage. My biggest worry would be the spinal injuries and whiplash injuries caused by the lack of support as the back of the buddy seat offers no support whatsoever.

 

[froggy]

The problem we have is that our Bay is a converted walk through panel van, that only has a 3/4 width rear seat with 2 lap belts, realistically this makes it a 4 seater.
Was looking at ways to safely introduce a 5th seat.
Have thought about maybe a seat that bridges the walk through gap, have seen these somewhere but cant remember where, the only problem is that we are also looking at fitting replacement front seats so dont know if it will all fit hence the buddy seat idea.
Is there any other way to get a 5th seat in the bay?