how & where to attach the new 3PT shoulder belt?

[PIExpress]

my newell motor coach only has a 2-Point seat belt for the driver and passenger seats (just the lap belt, no shoulder belt.)

I’d feel safer with a 3-Point belt. Any advice on where and how to attach the new shoulder belt?

Suggestions?
Experience?

Thanks.

[NewellCrazy]

What about this option with built in shoulder belts.

3412

[PIExpress]

Those are fancy have a link?

[Gone Busing]

What brand are those? I had seats changed out in a couple of pu's and suv's in the past and the last time I went to the van shop that was doing them locally they informed me they could no longer upgrade vehicles equipped with built in safety belts. They figured it might put them out of business some day. Now I see these.