The reasonable cost of probation determined under subdivision (a) of Section 1203.1b shall include the cost of purchasing and installing an ignition interlock device pursuant to Section 13386 of the Vehicle Code. Any defendant subject to this section shall pay the manufacturer of the ignition interlock device directly for the cost of its purchase and installation, in accordance with the payment schedule ordered by the court. If practicable, the court shall order payment to be made to the manufacturer of the ignition interlock device within a six-month period.