I did end up waxing the BMW this afternoon, picked some ceramic wax, which I had been using a spray wet wax, but since the car was dry...I do feel like the clay bar did make it easier to wax and buff out too.
FWIW, that is the actual top color - not black, can't remember what the BMW color code is, but sometimes people think it's faded. The back window is glass too, which is something they added to the Z4s.
I hate living in a state with dual plates, really sucked having to install that front bracket.
I didn't wax my Civic unfortunately, but will wash it again, and I usually do wax it before our first snow.