I was interested to know if anyone has replaced a 312 with a 412 on a dover t4 car, or for that matter any car. I was informed that thyssen would have to furnish software that would go into the new 412 drive. Is this true. I was under the impression that you could get a 412 drive off the shelf and put it in any car that already had a 312 drive in it with just the wiring changes to deal with. any ideas?