41 CFR §109-38.502-50 — DOE guidelines.

1. (a)Whenever practicable and cost effective, commercial service facilities shall be utilized for the maintenance of motor vehicles.
2. (b)Individual vehicle maintenance records shall be kept to provide records of past repairs, as a control against unnecessary repairs and excessive maintenance, and as an aid in determining the most economical time for replacement.
3. (c)One-time maintenance and repair limitations shall be established by the motor equipment fleet manager. To exceed repair limitations, approval of the motor equipment fleet manager is required.
4. (d)
   1. (1)Motor vehicles under manufacturer's warranty shall be repaired under the terms of the warranty.
   2. (2)When motor vehicles are maintained in Government repair facilities in isolated locations that are distant from franchised dealer facilities, or when it is not practical to return the vehicles to a dealer, a billback agreement shall be sought from manufacturers to permit warranty work to be performed on a reimbursable basis.