What did you do to your car today?

Hm, no idea man. But using some investigative super secretive GM TSB powers:

[Vin match]
[Alpine’s vehicle build date: 11/06]

MODELS:
2006-2007 CHEVROLET COBALT, COBALT SS
2006-2007 CHEVROLET HHR
2006-2007 CHEVROLET MALIBU
2007 PONTIAC G5
2006-2007 PONTIAC G6
2006 PONTIAC PURSUIT(CANADA ONLY)
2006-2007 PONTIAC SOLSTICE
2006-2007 SATURN ION REDLINE
2007 SATURN SKY

BUILT BETWEEN 4/06 - 11/06
WITH ANY OF THE FOLLOWING ENGINES
2.0 ENGINE (VIN P - RPO LSJ)
2.2 ENGINE (VIN D OR F - RPO L61)
2.4 ENGINE (VIN B OR P - RPO LE5)

a tick or rattle noise may be heard from behind the front cover of the engine and/or pieces of a timing chain roller may be found during an oil change.

Non-heat treated timing chain rollers were randomly installed in the assembly line hoppers. He advised that this happened sometime between 4/1/06 - 11/1/06 so it can randomly affect late 2006 - early 2007 models.