rear seat belts HA

[Bob perry]

I would like to fit some rear belts to the HA, now that my 11 year old Grandson is taking a big interest in the Viva!! Start em young eh?

He has ridden in the front, no problem, but when my Wife and I are there too, he has to go in the back, and moaned because there aren't any belts, so he wants to help me fit some!!

Haven't studied it yet, or removed the rear seat, but are there any pre formed threads for bolts and mounting points, or have I got to manufacture some.

Where's the best and strongest points? Probably going to get static three points, or would lap types be ok?
Presume the buckles would be under the seat towards the centre, therefore the top point would be around the parcel shelf area, but where would the bottom mounting point go?

Any views or assistance would be great, thanks.