I was on the motorway for like 5hrs straight and vibration developed from rear it got worse and worse till I could only do 40mph. I had already stopped and could not find anything wrong but in the end had to stop as it felt like wheel was about to fall off When I ran my flat hands round the tyres one was totally out of shape changed for spare... cured
When I showed the tyre to the garage they said It had started to delaminat probably from heat or faulty tyre
It was real scary when it happened M25 90mph 6pm and dark
Check your Tyres as it might not look to obvious.