Sit down boys and girls so I can tell you a story about the 1948 Lincoln Continental. Under that beautifully sculpted hood sits possibly the last V12 engine ever put in an American Car. The L-head V12 in the Lincoln was based off of the Ford Flathead V8 Bonnie and Clyde so famously drove around in. The Lincoln V12 produced 110hp and 180lbs/ft of torque from 400rpm. Perhaps not the most reliable engine but one that Lincoln should be proud of.
The prestige of a V12 is hard to argue against. Can anyone think of any other American cars that had a V12 engine after 1948? Vector doesn't count considering the engine was straight out of a Diablo.