Investigators said the teens learned how to make the dangerous bombs on the Internet.
Robert Jacob Browne, 19, and Mitchell Gary Melugin, 18, have been charged in last Thursday night's incident.
Two other suspects under the age of 18 could also face charges.
The sheriff's department said one of the bombs was thrown at a group of pedestrians in Laguna Hills and another was thrown into the open window of another vehicle in Mission Viejo.
Jim Amormino of the Orange County Sheriff's Department said the bombs could have caused an accident.
"You have exploding particles of plastic and dry ice - we should take this as a warning to anybody else. It's not a prank. It's a very dangerous thing to do," Amormino said.
There were at least six dry ice bomb attacks. Officials said it's just luck that no one was injured.