Any scrubbing and that reflective paint is in trouble. On mine the paint was already coming off in some spots, I cleaned w a sponge, and more came off. The plastic was red underneath the paint.
I ended up using rattle-can "chrome" paint to restore them. Be sure to remember not to paint inside the holes for the lights, it ruins the electrical connection (but easy to undo w a dremel and wire brush).
I cleaned the lenses w warm soapy water, installed all new bulbs, and it's a lot brighter