So you think auto parts are dull? Well, sometimes a simple sun visor can lead to international intrigue.

Prince Corp., of Holland, Mich., became a player in auto interiors when founder Edgar Prince realized a car's sun visor was valuable real estate. He put a lighted mirror on that visor and got rich.

In 1996, the company was sold to Johnson Controls for $1.4 billion.

Erik Prince, an heir to the Prince fortune, put his money into founding a security company, Blackwater U.S.A. Prince, a conservative Christian and big donor to the Republican Party, is the brother of Betsy Prince DeVos, ex-chairwoman of Michigan's GOP.

The publicity-shy Prince and his company now find themselves the subject of unwelcome headlines.

In 2004, four Blackwater employees were dragged from a vehicle in the Iraqi city of Fallujah, and their bodies were mutilated and set afire. The torsos of two of the men were hung from a bridge, and photos were shown around the world. The incident sparked an upsurge in anti-U.S. attacks.

The families of the four employees are suing Blackwater, alleging it failed to provide protection and equipment to the workers as stated in their employment contracts. They say that voids a clause in which employees waive the right to sue.

The suit is being watched closely in the shadowy back-channel world of international private security and could become a precedent for suits against other such companies.

Meanwhile, journalist Jeremy Scahill is publishing a book that could spark more controversy: Blackwater: The Rise of the World's Most Powerful Mercenary Army.

All that from a sun visor.