The problem is not with the rental car companies, but with the police. I have been renting cars for years in the States in various states and with all the major companies and never had a problem.
The issue arose when police in New York started to give out tickets because of the word - permit. (even though I was once stopped by a policeman on Long Island and it didn't bother him)
It is good to see that the MOT moved fast on this matter. Unfortunately my license is until 2015 so I'll have to think what to do when the new licenses come out.
Anyone know when that will be?