yeah, i agree. the wires should be self insulated. if one needs to put stuff on them (and you dont have a 3.8L 4th gen), then it might be time for some new wires.
they do make some nice sheathing to help protect wires (made of various 'lars), but it is too $$ for me.
If they're arcing, then they're toast like everyone said above.
My headers like to melt em, so after buying about 3 sets of wires, I finally found that wrapping the last few inches in tinfoil gives them enough heat deflection. If yours are arcing because they're old and abused, then it's time for those 9mm's you always wanted.
I had a set that the boot melted on (even and L boot shape) because of the euqal lengths (MAC Grr.). It would make my car stumble. I took a think walled piece of pipe and stuck the plug in it then connected it. No problems, no expensive header wrap for a 2" job.
if the wires are new and are arcing, i would make sure your plug gaps are not insane (not likely) and get the wires swapped under warranty, if you can. the jacket should keep them from arcing.