G'day Rod,
Glad to see you bought Morrie's Reek.
Like Rock said, most of us don't bother with a spare but if you must then here's how my new baby is setup.
The seat belt ends are simply bolted to the fibreglass at the appropriate spot to pull through the holes in the wheel and Bob's your uncle mate.
Just don't forget to carry extra wheel nuts or studs to suit the spare wheel if it is different from your road wheels
as in my case with mag wheels on the car and a standard VW steel wheel as the spare.
PP.
The Lifer.