Plenty of stuff on cars will never be seen by anyone but a mechanic or MoT tester, and even the manufacturers don't put much effort into its appearance.

Underbody braces, brackets and subframes, repair pieces for jacking points and sundry odd-shaped bits of bent metal that aren't pretty but have vital jobs.

Often these parts are manufacturer-only, there's no aftermarket, and when the OE calls time on their production, you're SOL (yes, even BMW's Mobile Tradition can't always save you)

So your options have been, seek out a decent used one, repair the one you have, or make a whole new one.

But if yours is buggered by time and rust, it's likely most of the other old ones are, too. Or if they aren't, they're bolted to cars that still need them.

And we don't all have the time, tools, or skills to fix ours or reproduce another...