Kent Police brought the car to a halt earlier using “tactical contact” near Junction 9, after it refused to stop.
A spokesman said an Army team attended “as a precautionary measure”, but the motorway had since been reopened after they declared the vehicle safe.
A man from Wales has been arrested on suspicion of dangerous driving.
The force spokesman said officers first attempted to stop the car as it travelled towards the coast “at excess speed” near Junction 12 just before 11:30 BST.
However, after refusing to stop, it left the motorway and returned to the London-bound carriageway, with police in pursuit.
He said officers followed it to Junction 9 “where a police car made tactical contact with the vehicle, bringing it to a stop with no injuries reported”.
“The Army’s Explosive Ordnance Disposal team attended the scene as a precautionary measure following concerns about the security of the subject vehicle, which has subsequently been declared safe and removed from the carriageway,” he said.
He added that the force wanted to “thank everyone for their patience and understanding whilst the motorway was closed”.