A search of the vehicle turned up two sawn-off 12-gauge shotguns, along with at least 40 live shotgun rounds and 13 .303 full metal jacket rounds.
Cannabis and about $50,000 in cash were also found in the centre console.
Tairāwhiti area commander Inspector Danny Kirk said it was exceptional police work.
A 30-year-old man is due to appear in Gisborne District Court on October 20, facing a range of firearms, drugs and driving charges.
Additionally, a 20-year-old woman, who was also in the vehicle, was arrested.
She is due to appear in Gisborne District Court on October 23, charged with unlawfully possessing firearms, ammunition and cannabis.