While post-marital contracts are only signed after the marriage has already taken place, marriage contracts are drawn up and signed when the couple is still thinking and planning their marriage. The couple has the opportunity to enter the marriage with full knowledge of the income, property and liabilities of their future spouse and to have already reached an agreement on important issues related to marriage and a possible divorce. 5.5 The parties expressly waive their rights to challenge this contract due to lack of autonomy, coercion, unauthorized influence, lack of will or lack of understanding. A terminating contract is not a substitute for a last will and a will. In addition, nothing in this Agreement shall prevent the Parties from designating each other as beneficiaries in their wills, trusts or pension plans. . . .