Such city shall have the power to fix the amount of fees, not exceeding $1.00 per test and not more than $2.00 per annum, for the inspection of any motor vehicle for any and all defects prohibited by law upon and for every restriction and requirement imposed by law with respect to the equipment and maintenance of any such motor vehicle operated upon the streets, alleys, or highways of such city. In addition to inspections required by ordinance, any owner or operator may have his motor vehicle inspected as often as he or she may reasonably desire, between such inspection periods as may be fixed by such city. Such city shall have additional power to set aside all fees so collected by it in a separate fund out of which all costs and expenses in connection with or growing out of the construction, establishment, equipment, operation, and maintenance of such stations by it shall be paid. Any surplus remaining in such fund shall be paid into a fund for traffic regulation and enforcement.