Oregon Revised Statutes Insurance § 742.460

Any motor vehicle liability insurance policy may provide that the insured shall reimburse the insurer for any payment the insurer would not have been obligated to make under the terms of the policy except for the provisions of ORS 742.450 to 742.464, 806.080 and 806.270 and it may further provide for the prorating of the insurance thereunder with other valid and collectible insurance.