 Final assembly of the M2 cars using Budd or Vickers bodies was completed at GE's Transportation Division in Erie, Pennsylvania.In the late 1980s and early 1990s, the M2 design was licensed by the MTA and ConnDOT to two other companies to produce follow-up series.Tokyu Car produced 54 M4 cars in 1987-1988, and Morrison-Knudsen produced 48 M6 cars in 1993-1995.