Within three years following the date referred to in the third subparagraph of Article 8 (1), the Commission shall carry out a detailed study to ascertain whether the anti-tampering measures for vehicles, particularly those in categories A and B referred to in Chapter 7 of the Annex to this Directive, can be considered appropriate, inadequate or too extreme in light of the intended aims. In the basis of the conclusions of the study, the Commission will, if necessary, propose new legislative measures.