Hundreds of people had to be evacuated after the pipe bomb was found in the parking lot of the Redlands Town Center on Alabama Street at about 1 p.m. Seven businesses in the area were affected by the incident.
A bomb squad team used a robot device to remove the suspicious device and safely detonated it.
Redlands Police said the couple's two small children were in the car when the device was discovered.
No one was injured and no additional devices were found. The scene was cleared shortly after 5 p.m.
Steven Sunny, a 28-year-old Victorville man, was arrested at a San Bernardino trailer park Monday night where his girlfriend lives. But police say Sunny actually lived in the high desert at a home in Victorville.
Sunny was arrested on three counts of attempted murder. He was held at San Bernardino County Jail on $1 million bail.
"We're pretty clear that the woman was targeted by her ex-husband," said Redlands Police Spokesman Carl Baker. "This ties in to a domestic dispute."