Police and the British Army's Explosive Ordnance Disposal (EOD) team were called to Motorhog in Empire Way at 12:15 BST on Friday.
Part of Bristol Road was closed and nearby properties were evacuated while a controlled explosion was carried out.
Police have confirmed there were no explosives in the package and are now investigating.
A suspicious package discovered at a vehicle dismantler's yard in Gloucester was "not a bomb", police have said.