The heating of the washer fluid with engine coolant lines is one of the most brilliant MB features, period. In cold climates, it is a HUGE safety device that means you can wash the windscreen during winter weather without icing up the glass.
That, combined with the heated nozzles and automatically heated mirrors make MB one of the best winter cars. And for those of you from Texas, Germany gets winter...
1998 C230 "Black Betty"