I'd LOVE a horse and cart though... that would be really cool. Can't see it going down well with other road users though who would be forced to drive MUCH more slowly than usual.
Oh what a shame that would be......
I once had a three wheel pedal trike that had a yellow cab ( made out of some old jcb side panels) and I kept getting slagged off for the same reason of slowing down the traffic. I also used to get hailed as a taxi as our town hackney cabs are yellow.... never tempted though.