i've got 3 belts in the back of mine, 2 inertia (one each side) and a lap belt in the centre. the inertia reals mount on the parcel shelf. i used belts from my old cavalier.
The only thing is series 1 might not have the mounts fitted, ok if its series 2 but better check they are there before sourceing belts.
Hope this helps
Richard
Webmaster