Police say the 36-year-old Barrie, Ont., man was involved in a minor collision on Saturday.
Barrie police say that when officers arrived it's alleged they found crack cocaine and a pipe.
The driver was charged with possession of a narcotic and impaired driving and police say the rental vehicle he was driving was confiscated and will be held for 45 days.
And investigators say the accused man's girlfriend became upset over his arrest and allegedly opened the police cruiser door in an attempt to free her boyfriend.
The 31-year-old woman is facing a charge of obstructing police.