N.M. Stat. § 55-2-202
Final written expression; parol or extrinsic evidence.
Terms with respect to which the confirmatory memoranda of the parties agree or that
are otherwise set forth in a record intended by the parties as a final expression of their
agreement with respect to such terms as are included therein may not be contradicted
by evidence of any prior agreement or of a contemporaneous oral agreement but may
be explained or supplemented:
(a) by course of performance, course of dealing or usage of trade (Section 55-1-303
NMSA 1978); and
(b) by evidence of consistent additional terms unless the court finds the record to
have been intended also as a complete and exclusive statement of the terms of the
agreement.