[Paul]

(I thought Polar and Chargemaster were the same network?)

Yup.

 

[Paul]

Hmm, I wonder, can any of the schemes "roam" to Milton Keynes, and if so, at what price? The Polar / Chargemaster price, or the price of their own scheme?

 

[Paul]

They certainly aren't supposed to be free.

 

[Paul]

Yes, as @MrPudding says it's not BMW owned it just happened (coincidence I'm sure!) to be put right on their doorstep on a public road.