Has anyone tried fitting MK5 proper seatbelts

ie 3 point into a MK4 ??

Can you use the plastic trim that guides the seatbelt over the top of a MK5 seat and attach that into a MK4 ???

Then it should be just a case of moving the " reel " to the boot and using the side mounting point as the lower corner one ????

Want to do this so I can make a Cabriolet more child safe

Cheers

Mark