seatbelts in a ragtop

im just about to place an order for a new hood and a set of seatbelts etc for my sIII. it used to be a hardtop. how do you fit seatbelts to a softtop - or do you not fit 3 point belts? are lap belts legal for all three seats? or is there a specific part required to allow fitting of inertia reel belts?

any help much appreciated.
J

This is what i fitted.
Part no 514/30
Exmoor Trim & Trakkers

thanks for the info - ive ended up ordering the full restoration kit from exmoor (seats, belt, hood)
J