If you have a spare $200K or so, a barn find pair of '87 Grand Nationals with sequential serial numbers is up for sale on Ebay. The cars have been together for 30 years. One has 500 miles, the other 800.
https://www.ebay.com/itm/1987-Buick...c7f894b11e&AdChoicePreference=true&rmvSB=true
https://www.ebay.com/itm/1987-Buick...c7f894b11e&AdChoicePreference=true&rmvSB=true