OK, so I just washed my car last night, but I noticed something this morning. I have hard water spots over one of my windows, door, and the hood. On the paint, the waterspots have taken on the SLIGHTEST tone of coloring. Normally I use Meguiar's NXT Car Wash, then I use the Mr. Clean water filter, which has always worked fine previously. I noticed last time I left some spots though, and washing my car yesterday didn't remove them. So, does anyone have any advice to get rid of these spots, or other hard to remove things from your car? For instance, on the same door previously mentioned, I have a bit of cement splatter on the bottom of it that just won't come off 100%. Any tips are appreciated.