Ds is 4 in July 14 weighing 14kgs. We have arranged for a hire firm to pick us up at Lanzarote airport which is apparently a 15 min drive ( puerto del carmen). Not sure if we should take our normal car seat ( 5 point harness) or booster seat ( just the seat without a back). I am leaning towards our normal carseat as is the safer option. What would you take?