I sort of get it, but, say you can only view a vehicle you are hoping to buy after normal working hours, you go to see it in the evening, how do you drive it home if you decide to buy it? The government are trying to get us to cut emissions (apparently) but surely, two trips, one to view, one to drive the car away away once you've taxed it just puts more emissions into the air....just saying!
Unless, it's ok to drive it home, then the next day, the seller claims a refund and you tax it.......... do you think that is what they are thinking........