Two graduate students die after a speeding luxury automobile slams into their vehicle

The dash cam video is jaw-dropping: On a virtually empty stretch of highway, a midsize car is seen traveling in the slow lane. Suddenly, a black Mercedes-Benz zooms into the frame and rear-ends the car at tremendous speed. Within a split second, a cloud of smoke and debris fill the video screen.

What happened next is now well known in Thailand and the focal point of growing outrage. The midsize car burst into flames and the couple inside, both graduate students in their 30s, died at the scene of the accident. The Mercedes driver, the son of a wealthy Thai businessman, survived with minor injuries and refused both alcohol and drug tests - and his wishes were respected. Police say he was driving at an estimated 240 kilometers per hour.