I have just got of the phone from Motability yes the limit is 20,000 over the 3 year lease, however if it only 1,000 or 2,000 miles over they are not going to object, if it was 24,000 plus that may be a case by case decision.
Thanks for updating. Interesting that the 20,000 mile cap for an extension is still in force (as we weren’t sure) but odd that the wording of the new leases still says that it can be extended beyond 3 years, with no caveat about mileage. Left hand….right hand!