mondeomark

Hi all i am thinking of buying my wife a mk4 cab but i have been told that they only came with lap belts in the rear. We have a 4 year old that will have to sit on a booster seat can we put a booster seat in the back with lap belts? or can we convert it and fit normal seat belts in the back? I could do with knowing b4 i end up buying something we can not use as a family