ERF carseat for back seat of Ford Ka (new model)? Anyone have one??? Help please

Has anyone got a Ford Ka and an ERF car seta that is safe to go in the back seat of the car using seat belt only? I really wanted the besafe Combi x3 but from what i understand it can go in the front seat only. I am a bit unsure about putting the car seat in the front would it not be less safe since most accidents happen at the front and obviously the air bag will be de activated for baby.  Any help greatly appreciated thank you! (I am abroad at the moment so cannot go into a store to find out what fits. Here they dont seem to have any ERF! )