Won't t 3D-printing metal appliances be more and more widely feasible in coming years? And, at least here in the EU, right-to-repair [1] labeling gives consumers the ability to more efficiently vote with their wallets. Its also happening in the US [2]
Liquid steel requires enormously high temperature and magnesium/aluminium require an argon atmosphere. Titanium requires both. So unless you're going to make everything out of zinc (assuming we don't run out of zinc!), this may not be the cheap fix you're hoping for -- and zinc isn't very strong.
There are also many types of steel that have widely varying properties.
There are some (expensive) printers that print powdered metals (including steel) that is later sintered in an oven. They're certainly not large enough to make a car, and even if they were the properties of the material are likely not ideal, and the process would be prohibitively expensive.