Four weeks ago the Society of Motor Manufacturers and Traders (SMMT) stated that if there were No Deal with the EU and the UK has to trade under WTO rules then the cost of imported cars from anywhere in the World, not just the EU – would rise by 10% (average price for ICE car currently £19k = extra £1,900; average price for e-cars £30,000 = extra £2,800). Tariffs of up to 22% would be placed on vans and lorries.
If we have to Trade under WTO rules then tariffs will be applied to vehicles not only imported from the EU but from anywhere in the World:
“WTO rules state that the same trading terms must be applied to all WTO members, unless, for example, there is a trade agreement between 2 or more countries. This is known as Most Favoured Nation (MFN) treatment.
MFN means that the UK cannot offer better trading terms to one country and not to WTO members, unless, for example, it has a trade agreement.” (Gov.UK website ‘Trading under WTO rules’)
https://www.gov.uk/guidance/trading-under-wto-rules
If they do come up with some kind of Deal then, obviously, we will apply those rules instead.