Terms with respect to which the confirmatory memoranda of the parties agree or which are otherwise set forth in a writing 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 a prior agreement or of a contemporaneous oral agreement but may be explained or supplemented:

1. (1) by course of dealing or usage of trade or by course of performance; and
2. (2) by evidence of consistent additional terms unless the court finds the writing to have been intended also as a complete and exclusive statement of the terms of the agreement.

Added by Acts 1993, 73rd Leg., ch. 570, Sec. 1, eff. Sept. 1, 1993.