Firstly utter bollocks. it's illegal to attempt not to pay road tax on a vehicle which is not legally tax exempt.
secondly don't take ya vehicle to North Wales. Plod ther love "Mulitagency vehicle inspections" and operate road side inspections with Police, VOSA, DVLA, Benefits Agency. Environment Agency & HMRC. vosa & dvla are there to check legallity of vehicle C&U Regs etc. HMRC for dipping fuel. Benefits Agency to check that you'r not claiming benefits whilst driving a van full of building tools etc. and E.A to make sure your licenced to carry any waste that you have on the vehicle.
They recently had one outside Bangor Hospital and fined all the midwives, community nurses etc, £60 for not having "No Smoking signs inside their private cars. On the grounds that they were using them for work (visiting patients) and therefore they were works vehicles..
another reason to not visit a ****hole