Article 43 EC must be interpreted as not precluding legislation of a Member State under which a motor vehicle, which is registered and is already the subject of taxation as a result of its registration in another Member State (Belgium), is the subject of a tax when it is first used on the national road network (NL BPM), where that vehicle is intended, essentially, to be actually used on a long-term basis in both those Member States or is, in fact, used in that manner, as long as that tax is not discriminatory.