It’s such a non-problem it’s not even worth mentioning.
The surface of the Earth is big. If you place 40,000 car sized objects on it in random places, you’d not be able to see then from low earth orbit.
That’s approximately how irrelevant they are in the sky.
This overlooks that the Rubin telescope has a relatively wide field of view and a thirty second exposure time, so LEO satellites do routinely appear in images. The size of the object isn't so important as its relative brightness, so while a car on the surface of the Earth is hard to locate from 400km above, a sunlit car 400km up in the night sky is visible to the naked eye.
Its a non-problem, until it is a problem .. and, wouldn't you want to know in that case?
Especially[0] if we can blast the thing out of the sky, one of these days ..
[0] - https://c.tenor.com/o9t2JYNU4LYAAAAd/tenor.gif