Dr. Elliot Reid, played by Sarah Chalke, looks horrified when she hears about Dr. Burke’s suicide because she suffers from low self-esteem. When she tried to raise her spirits by purchasing a new car, it just became a fricking disaster. Her biography on the web site for the show quotes J.D. as saying:
"Both Dr. Kelso and I had heard enough of Elliot's inspirational stories to know that they inevitably end with someone killing themselves."
The clip is from My Way Home, which is the 100th episode of Scrubs. It is noted for many references to the Wizard of Oz - in which Billie Burke played Glinda, the Good Witch of the North.