Every City owned motor vehicle damaged as defined in the subdivision (1) of Section 3.84.010 shall be removed to the municipal shop for repairs as soon as conveniently possible following the accident, but in no event more than 7 days thereafter; provided, however:
A. That no vehicle shall be repaired without prior authorization of the Commissioner In Charge of the bureau to which the vehicle is assigned, or his authorized representative, except in the event of emergency whereupon the said Commissioner shall be notified within 72 hours of all such work done; and
B. In no event shall any vehicle be repaired by other than a City owned and operated repair shop unless and until the Purchasing Agent of the City shall have first obtained at least three independent estimates of cost of repair, and in such event the repair work shall be awarded to the lowest responsible bidder.