Quote from wikipedia:
The chassis of the Allanté was made in Detroit, then was loaded onto specially equipped Boeing 747s and shipped to Italy where the body (which was designed by Pininfarina of Ferrari fame) was mounted to the chassis. Afterwards, the cars were loaded back on the jetliners and shipped back to the Detroit/Hamtramck Assembly plant in Michigan for completion. This led to a few interesting nicknames, such as "The Flying Italian Cadillac" and "the world's longest assembly line."