I have a 99 S320 LWB with just 37k miles. Had friends in the back seat last night for the first time since I bought the car one year ago. They complained that there was no heat coming out of the heat ducts under the seats (not the center console vents). The only way I could get them comfortable was to turn up the heat, put the fan on high, and set the vent controls to both dash and foot vents. This is my first Benz and I could not figure out if this is normal or if there is some magical way to get warm air to come out from under the seats. The user manual was no help.