Try Victor wood KIA in Grantham. I bought my Carens from them last year and service has been superb! Sorted couple of warranty probs very quickly and yet again replaced my EGR under warranty last week.My brother in law lives in Newark and he also bought a Carens from Victor Wood. Had a warranty query, brought it in, they gave him a courtesy car at no cost.
My mate is on his 3rd Ceed and his second Sedona and won't go anywhere else. He made the mistake of buying his last Ce'ed from a Lincoln KIA dealer to save £200 but quickly found out the service was non existent and eventually KIA UK made the Lincoln dealer pay for 3 years servicing at Victor Wood.