I crashed on the ring, my insurers paid out for the car and for the circuit, normal insurance with a bog standard underwriter.

Lots of insurers will try and claim you arent covered on the ring, but german law states differently it would appear, you certainly will have NO problem at all in terms of damage done to the ring from what the officials there told me, but its only the third party liability that the law enforces so strongly, the comprehensive element of any insurance policy seems to be much more up for debate.