Delphi Automotive at CES 2015. Image source: Delphi Automotive.

What: Oh, how quickly things can change. That's likely what investors in Delphi Automotive PLC (DLPH +0.00%) are thinking after the stock had rebounded earlier this week after concerns of the U.K. leaving the European Union faded. Now, though, we know that scenario ended much differently than the world markets anticipated, and that result has sent shares of Delphi Automotive down 12% on Friday.

So what: Delphi is a former parts-supplier unit of General Motors, and is now a current supplier to GM, as well as Volkswagen and Ford Motor Co. The company is based in Gillingham, U.K., although much of its operations are run out of Troy, Michigan, thanks to its proximity to Detroit's "big three."

Thanks to the "Brexit" vote tallying in favor of the U.K. leaving, the U.K.-based supplier's investors are facing more uncertainty than they have in quite some time. On top of that, some of its major customers, such as General Motors, Volkswagen, and Ford, all do a significant amount of business in Europe, which could take a hit. There's no question that Delphi will be negatively impacted by this development, and the company generates roughly one-third of its total revenue from Europe.

Now what:  Further, Delphi's regulatory environment will change as the U.K. and the remaining EU members take a couple of years to figure out exactly how all this is going to work for trade and other factors. There's no question that it will negatively impact a number of Delphi's customers, who will deal with changing regulations, as well, but also a near-term slowing U.K. economy.

However, investors should consider this a speedbump in the grand scheme of things. Over the long term, Delphi is still very well poised to take advantage of trends within the automotive industry that aren't changing. Those trends include autonomous driving, increasing safety regulations, a push toward greener vehicles, and vehicles more connected with technology.