I don't know of many new plastic clipped knives, but is this just a preference or is there a specific reason you prefer them? The people I know that like plastic clips like them because they won't scratch up the cars they work around.
If your reason is similar, there are more options...supposedly wire clips are less likely to scratch stuff (there are no edges, it's a bent cylinder), and I've been thinking about cutting up old jeans and super gluing them to an old pocket clip for stealthyness and sheeple protection...mostly just to do something fun, but in any case, if you glue jeans or something to the outside of the clip, I imagine it wouldn't scratch up stuff either.
Of course, if you just like plastic clips, these things won't help much.