Not sure what you're 1991 Cadillac is worth? Many consumers don't know what their used car is worth, which leads to them losing money when selling their 1991 Cadillac or using it as a trade-in when buying a new car. Don't let this happen to you! Below you can look up your exact 1991 Cadillac price. Indicate your milegae and vehicle condition to view your 1991 Cadillac car retail and trade-in values.