planning on replacing the door components soon, just wondered what front and back speakers sizes are? 6.5" is usual i think but that was in the ibiza......and will i need to buy adapers to screw them back into the door card?

no-one?

yep get golf mk4 speaker adapters to fit 6.5inch in the front doors and 10cms in the rear side shelves

A search should furnish you with a fitting guide inc speaker sizes iirc.