Vehicles exempt from paying the tax: Old vehicles constructed before 1 January 1973 (historic vehicles) All vehicles except buses and lorries used commercially, that were constructed before 1 January 1973 may tax in the 'historic vehicle' tax class.ubmit. · just now. Report Abuse. A car has to be registered before 1973 before it is tax exempt...we had a VW camper and were looking forward to being exempt at 25 years old, but when I checked with ministry of transport I was told it had to be reg before 1973!!!!