i am interesting in buying an s320cdi mercedes long wheel base car. i will use the car for communting and taking my family on days out (my sons are over 6ft tall so room at the back is nice). a budget really no more than £15k. are these reliable cars or will it give me a lot of trouble. i have heard bad things about mercedes rusting, do these rust. my sons have outgrown the accord we run, it is a miserable boring car but reliable.