About a million, depending on who is reporting it, GM trucks and cars from 2006 up are being recalled due to a short in the windshield washer fluid heater. These seem to be high end cars and trucks. Right now there is not a lot of clear info out there; just that the recall is to be announced.

It somehow concerns a ground wire malfunction.

The only Mercedes I have had with heated washer fluid was heated with a metal coil that allowed coolent to flow through the washer bottle. Looks like Mercedes knew what they were doing in that area.