Gardaí in Dublin are questioning a man in relation to the explosive device discovered and disposed of in County Clare yesterday.
The man was arrested in Dublin under Section 30 of the Offences against the State Act and can be held for up to 72 hours.
The device, which was big enough to blow up the vehicle and kill any occupants, was dismantled by Army bomb disposal experts from Cork.
The alarm was first raised at 8.20 am yesterday morning when a man received a telephone call warning him that there was a bomb under his car, parked on a driveway in Doonmore, near Doonbeg.
He informed gardaí and the bomb disposal team arrived at the scene at 12.30pm. The area was sealed off until the device was made safe an hour and a half later.
An army spokesman said the bomb was a viable device containing 150 grammes of explosives. "It was big enough to do a lot of damage," he said.