Section 18
SEC. 18. Disposition of motor vehicles not used by a bureau or office.-All motor vehicles owned by or assigned to the different departments, bureaus, offices and branches of the National Government not needed by the officials and for the purposes enumerated in section 13 and 15 of this Act shall be disposed of to the highest bidder at public auction sales announced in newspapers of general circulation at least ten days before the sale: PROVIDED, That the former user thereof shall be given preference if he offers a price equal to that of the highest bid by others.