You can't tax it with a vic marker, that's how the trap works, any car that needs a vic will only be able to be used untill the tax runs out.at which point it shouldn't be able to be re taxed untill the marker has been removed. As far as I'm aware the post office will refuse to issue tax on it.

The v5 won't be issued untill the vic marker has come off, only then can you tax it.

Any that have been taxed probably don't have a vic marker

It's not pub talk, I used to do vic testing when I worked at vosa, and that's how the vic scheme is supposed to work. Many many cars that owners think need a vic test, and have a vic marker actually don't though!