The post you are reporting:
Technically, if you are a UK resident, you can not drive a foreign-registered vehicle in the UK at all, even if you own it and it is taxed and insured in its country of registration. If you are a bona-fide visitor you can drive it for up to 6 months. Nationality is irrelevant. Visitor means 1. you are permanently resident outside the UK AND 2. you have only come temporarily to the UK.
If you come as a visitor but then start looking for a job, getting an NI number and renting accommodation, then you are immediately a resident and your car must be MOT'd, insured, registered and taxed in the UK.
Foreigners (even EU nationals) who travel to the UK to settle are committing an offence if they use an imported vehicle on foreign plates. If the driver of a foreign-registered vehicle is stopped by police and gives a UK address he is deemed to be resident and the vehicle is subject to seizure. Over the years I have imported three vehicles into the UK on foreign plates so I am familiar with the law. On two occasions I was a bona-fide non-resident with a foreign address but on the first occasion, when I was UK resident, customs asked me why I was driving a vehicle on French diplomatic plates with a British passport and my 17-year-old niece (a French resident) who was with me in the car had to drive the car back from Dover on her brand new L plates. Scary. It was the first time she had ever been behind the wheel of a car.
These rules are uniform across the EU so people who move to France or Spain permanently but keep a UK-registered car, popping back once a year for MOT, are also breaking the law.