Wash it again; but with hot, SOFT water. Water spotting happens because the minerals in the water (mostly calcium) are attracted to the surface of the paint/clear coat. Soft water neutralizes the minerals 90% plus (slight variations occur with different mineral mixes in the water). The minerals therefore float up into the water droplets instead of sticking to the bottom of them, against the paint. While the water is beading, lay a good quality microfiber drying towel down and lift it off with the lightest of pressure; move to the next section and repeat; start at the top and work your way down. One 2' x 3' drying towel will be enough for this sized car, even counting the glass (you can rub the glass to polish it, and that is the opposite side of the towel - the close knap side - from the looped pile side that is used for drying the painted surfaces). Only use the towel once then launder (follow instructions or you'll compromise or ruin the towel). Never dry with an already soiled microfiber towel. I don't use any cleaning products when I wash my car (but then, I don't let my car get dirty just a layer of light dust is enough to make me give her a bath); just hot, SOFT water, using 100% terry cloth towels, light pressure, no rubbing; followed by the microfiber trying towel. My car is never spotted.
(Swirl note: a Silky Silver finish does not show swirls in the clear coat like say a Black surface would. My method of just using hot, soft water may not avoid swirls like a more involved wash method using dedicated cleaning solutions, followed by polishing. But regardless, the most important aspect is to avoid hard water at all costs. If you can't get soft water, then add a solution that will turn your bucket of water soft, in other words, soften your water by hand. I've never had to do this, so I can't recommend a specific product. Somebody else might be able to do that: I just know that if you don't use a product that duplicates the mineral neutralizing property of soft water, you'll be fighting a constant battle against water spotting.)
