Is it okay to put unnecessary stuff in the orbits around our or other planets? Isn't this space trash that can potentially be problematic for future endeavors? Are we creating problems for ourselves to satisfy our vanity?
If it gets to be a problem in the future, it will have so much historical value that someone will launch a mission to go fetch the Roadster and bring it home to Mars.
Anyway I wouldn't normally consider it to be space trash, but in this case it's pretty much just a big Tesla ad billboard orbiting the planet so I agree with you sentiment
Space debris is a problem in a small number of high-traffic Earth orbits. There is almost nothing in existence on this random Hohmann transfer solar orbit where the car will live for hundreds of millions of years.
Space is big.
It probably does not add a measurable amount of junk to hit than is already up there in the form of natural rocks.
Though if in the future human population hits the quadrillions and we are living on all 8 planets we should probably start worrying about our space trash.