I don't know anyone that pays no tax but I do know many that over inflate their costs and expenses to offset their tax liability.
Because I don't take the piss I ended up getting double back from the self employed help that most of my mates got.
That helped me to keep my C63 on the road..... Now that's an expensive hobby but if road taxes went under the umbrella of income tax they'd probably get even less income from all the folk dodging tax