I believe you can order new shrouds in white or black.
IIWM, I'd epoxy-sandwich a new piece of plastic around both sides of the broken part. You can use a section of plastic off a heavy duty blister pack, old credit card, etc., then spot paint it for UV protection. I've repaired a couple of mine that way over the years & if done well it holds up fine.
Don't patch w/any part of a stimulus check, it ain't durable & won't last
Although if it flew off the coach it would certainly bounce.
Ace hardware has spray paint for plastic, probably also HD & Lowes.