Speaking at the University of Delaware Thursday, Elon Musk took a  public swipe at rival Fisker automotive, whose electric vehicles  may become  competitors to Tesla's .

Fisker whose NINA vehicle is slated to go into production soon in a new Delaware facility, faced a 2008 lawsuit from Tesla  in which Musk alleged that Fisker co-founders Henrik Fisker and Bernhard Koehler used a sub-contracting  job for Tesla to gain access to confidential information before announcing their own competing vehicle.  A judge ruled in favor of Fisker and ordered Tesla to reimburse Fisker's attorney fees.

During his Thursday presentation, Musk said that  there are sizable engineering obstacles to building an electric car and "Fisker is very far from overcoming those."

Pretty harsh stuff, particularly when speaking to Delaware residents, a group who are currently betting public money that a new Fisker factory in that state will turn out to be an economic windfall.

Fisker, who recently fired back at Fox news in response to some negative and slanted reporting, is not known for taking public attacks lying down.

How long will it be before the gauntlet is taken up and rhetorical stones start flying toward Tesla?