Learned a lesson today. A few years ago in the frigid cold in the dark I dropped the black plastic valve stem cover on my wife's car since the air pressure sensor was lit on the dash. I couldn't find it in the snow and rocks, so I had one of those chrome caps and used that. Fast forward 3 years, I go to take that cap off and it has locked itself in place. Broke the valve stem and had to buy another one of those fancy digital reader valve stems at $70 each. So if you use those chrome/aluminum valve caps, use some anti-seize on the threads!