I just bought a c280 after having owned an s420 and it is definitely cheaper, the radio will not turn up. In the s class the radio was excellent and never had a problem, I posted yesterday and had views but no answers I wouldn't think this was an uncommon problem with this model? The radio and c/d player work but can only turn the volume down and not up loud enough to hear very well. The car is a 2006. Also does anyone know what is easier on the life of transmission, comfort or sport? Thank you!