There are a number of rules that one needs to be aware of.
1) A car from another EU country is allowed to be on the road in another EU country for a maximum of any 6 months in any 12 month period. However if the car is not on the highway in another EU country then it is allowed. Best advice is cover the car when 'off road' so that neighbours can not see the foreign number plate.
2) It is actually an offence for a resident of an EU country to own a foreign plated car in the country of residence.
3) The car needs to be 'street legal' in country of registration i.e. tax, mot, and insurance. Now comes the rub.... most if not all UK companies will not insure a car abroad for 12 months. However a few insurance companies here will insure a foreign plated car for the 12 months and also allow it to be driven to, say, the U.K. for serveral months. So far so good!!! However DVLA will not road tax a car with a foreign insurance policy. So if you keep a car abroad after the expiry of the road fund thingy you can have problems. Also a U.K. car has to have a current U.K. m.o.t. for U.K. usage. So if that expires before you return then the car is not legal anywhere in the EU. If it is only a matter of days then the best thing is to BOOK your mot for the day the car 'hits' UK land and when stopped by the UK police you are allowed to drive an un MoTed car if it is going to an MoT station.
The above is the Law....however here there are lots of foreign plated cars that have been here years and not been stopped....yet. So long as you are not stupid the chances are that you will not have any trouble here with the police especially if the car will be off road.
The choice is yours but remember that if a car is not 'street legal' and you have a 'major' crash/insurance claim then the insurance company will look at all details and if possible find a way not to pay any claim.
Sorry if this confuses the matter more but normal people do not write the Law!!!!!!