N.M. Code R. § 12.2.4.17
On approved credit: It is an unfair or deceptive trade practice for a dealer to advertise a specified finance rate and then have a customer sign a contract with a higher finance rate, unless the advertisement discloses the information specified in Section 18 [now 12.2.4.18 NMAC] for the loan program under which the low rate is offered and:
C. the transaction is not eligible for the loan program.
[5-1-98; Recompiled 10/15/01]