John Delorean Originally was going to have a stainless steel frame. He even made a speach about it stating that "even Rolls Royce doesn't do that." In the same speech he talked about the 25 year warrantee. Exactly why the car was not built without a stainless frame is not documented to my knowledge. Rumors though are: 1. Difficulting in welding stainless. The weld are not longer stainless. Some rust problem could have occurred. there. 2. Stress at the weld joints. THese would have to be heat relieved. (A lot more is now know about welding stainless than was known in 1979. That is why Brian Pearce has been able to develop the SS frame. On the other hand Brian and His dad are really great engineers and this may be the best expanation. 3. Possible concern about brittleness in the cold weather. (I don;t believe this one.)