Car is telling me to check Windshield washer fluid. Can I replace with the standard blue stuff thats like $2 gallon or is there a specific MB kind I am required to use?

 

Anything goes just make sure the cheap stuff will withstand the cold winter days.

 

Try to avoid RainX brand ww fluid - according to posts on here, it can cause problems with the spray pump system. I have to confess I used RainX off and on in my MB's since 2009, but was never aware of this issue and didn't experience any problems. But why take the chance? I've stopped using it.

I've also used the green stuff you can get at Costco and it's fine - it's good down to -45 deg C.