Judgment of the Court (Sixth Chamber) of 29 April 2004 in Case C-372/97: Italian Republic v Commission of the European Communities (State aid — Transport of goods by road — Effect on trade between Member States and distortion of competition — Conditions for exemption from the prohibition set out in Article 92(1) of the EC Treaty (now, following amendment, Article 87(1) EC) — Existing aid or new aid — Principles of reasonableness and of the protection of legitimate expectations — Mo)