We are trying to make sense of the regulations for Madrid. We can't get a sticker as our vehicle is not registered in Spain. Some websites say our French Crit'air sticker will be accepted....but not in Madrid. We only want to go round Madrid on the M-50, part of which is in the LEZ. Is it "excluded' as it is part of the motorway system? Even if it is, do we have to register our vehicle with the Spanish authorities which appears to be a requirement for foreign vehicles before entering a LEZ? Any recent experience would be helpful.