Since I didn't get much response on this question in the Detailing forum, I thought I'd post it here in hopes of some insight.
I purchased some of the concentrate that is suppose to go into the windshield washer tank. It's a genuine Mercedes part, called Formel VR 9422-15 Summerwash. It comes in a small plastic vial which holds 40 ml (1.34 fl oz).
The directions for use say:
Window washing agent. 1 bottle + 4 l water. Only mixable with Winterwash.
The part about adding the contents to 4 liters of water I understand. But I'm not sure I understand the part about "only mixable with Winterwash." Is it implying not to mix with other brands of W/W fluid, and only to mix (if at all) with Winterwash, another Mercedes product? (Which I'm guessing is an anti-icing product?) Anybody know what Winterwash is?
Thanks for your help.