Benson, You are perfectly correct as to the trouble i am facing. Yes, the desired line style were the VW defaults, plus a few custom I had added. I would have no problem with the Autocad styles coming in IF they did not re-order the styles in the palette, thereby messing up all the objects relying on those styles. I agree completely that it seems like a bug, and your suggestion sounds like a perfectly logical solution.
A further complication to this is that the line styles can only be recognized via graphics rather than by say a set number, or set name, so when they do get re-ordered in the palette it can be very difficult and time consuming to find and apply the proper one again.
Mike - how would one do this exactly? When the file is imported it automatically puts the new line types on the top of the list, bumping out whatever was there before...
Thank you both for your time and suggestions - quite helpful!