There does not appear to have been any duress or undue influence in their divorce. Therefore, Peter and Susan had genuineness of assent. The fifth element of a contract is writing and form . The statute of frauds requires that a contract for more than one year be in writing and form. The divorce contract between Peter and Susan had writing and form, therefore it meets the statute of frauds requirements.
Lawful object is the sixth element of a contract.
The divorce between Peter and Susan does not have lawful object. Peter and Susan are residents of New York state. Peter and Susan assumed residency in Mexico only with the intent of getting a divorce. The dissolution of Peter and Susan marriage is illegal. Since, there is no adequate remedy of law , it is the responsibility of the court to find an equitable remedy for the dissolution of their marriage.