[psim1]

In my state, annual automobile safety inspections are required. I have always been suspicious of this because naturally the auto shop doing the inspection offers to repair any flaws they discover. In most cases, the safety issues are obvious (thin tire treads, worn brakes, rust damage) so if you have a little bit of understanding you can verify the shop's claims and seek repairs elsewhere if the cost is too high.

[bombcar]

California has "test only" smog stations, though this was mainly to combat stations that would "just pass everyone" but they couldn't prove it.

Something like that can be worthwhile if you don't know who to trust; find someone who doesn't sell anything but the test.