Typically a washing, white vinegar and water solution, or a clay bar will not remove the water marks, they only work when it's a light residue on the surface. Unfortunately many water marks actually lightly etch in to the surface and in these instances you'll need a stronger option.
The Chemical Guys Water Spot Remover can be used to remove light etchings that are hard to see or feel. This is a really strong cleaning formula that should be used with care.
The more traditional option is to polish that area, starting with a less aggressive polish to a stronger one. I would suggest starting with medium pressure and a polish like the Meguiar's M205 and move up to the M105 if need be.
If that doesn't work you may need the extra power of a buffer to help work those polishes in. With the help of a buffer you can remove the majority of the surface imperfections from water marks and you'll also remove some of the swirls and oxidation so the entire surface looks like new again.
For the glass we recommend the Glass Science Glass Scrub, which does a great job of deep cleaning the exterior glass and removing water marks.