Very dirty D3 F30 with a 'D3' plate heading North on the A1(M) in commuter traffic. You went past me at Ledsham (A63) junction then I sat behind you until joining at the A1 M1 junction. You continued North on the A1(M) and I turned off on the A64. Travelling at typical 'Alpina' pace. I was in the equally dirty Carbon black F11 530d with black wheels.