1) I like interesting window shots, there are some pretty good photographers that have extensive window/door portfolios.
2) I'm not a big fan of B&W car shots unless it's a really old car.
3) See comment # 1 with the washers(substitute hardware for windows) although normally the focal point would dominate the shot a bit more. Those kinds of shots are difficult to make work (make people want to view them, evoke a reaction).
I can see you're looking at things to shoot with a creative eye so stay at it.
I was down in Baja this spring and took the shot below. My buddy's wife was so enthralled with it she made me shoot just about every door in town and since had a bunch of them framed. I didn't think it was anything special but it she sure liked it.