So this video begs the question to a dumb ‘Merican like me, what ARE the import laws for Aussieland?

They weren’t allowed to bring a whole car into the country, but didn’t explain why. If it was North America, it be because it wasn’t old enough... so is there an age LIMIT? Or are they not allowed to import ANYTHING regardless of age?

I’m curious and don’t want to spend hours on Google trying to decipher the gory details, I figure someone here would know the quick answer.