this is the only modern car seat well documented used to replace seats in an older car.
sebring seats There are quite a few modern trucks that use integrated seat belts, but I have not seen any other cars that do.
No aftermarket company offers seats with seat belts built in. I have looked for a while.
none of the companies that sell to the oem will sell to you or me.
most of these cars are pretty torn up to make them parts cars.
the ones that I have found that are not, have been hit in the front, so the seat belts are useless.
good luck.