A Long Island plastic surgeon was caught with an enormous cache of weapons in his car — that included five fully loaded assault rifles, body armor and more than 1,600 rounds of ammunition, police said Wednesday.

Tuckahoe Police officers looking into a report that Matthew J. Bonanno, 47, had threatened his estranged wife arrested him Tuesday at a bar in the Westchester County town for allegedly illegally possessing a Glock semi-automatic handgun.

When they searched his BMW SUV, they found a staggering arms collection.

Inside the backseat and trunk were the assault rifles loaded with high-capacity magazines as well as: three handguns, 29 more high-capacity loaded magazines, a stun gun, handcuffs, full face masks, multiple military-style knives, four brass knuckles, pepper spray, scopes, binoculars and other paraphernalia, cops said.

Police then searched Bonanno’s home in the Town of Mount Pleasant, where they found three additional unlicensed handguns.

At the surgeon’s other house, in Great Neck, cops discovered another armory of assault rifles, a shotgun, handguns, high-capacity magazines, body armor, hundreds of rounds ammunition, smoke grenades and other weapons, which were turned over to Nassau Police.

Bonanno, who practices in Lake Success, was arraigned Tuesday and remanded without bail on a slew of weapons charges. Investigators are still looking into how he obtained the massive amount of weapons.

He’s being held in the Westchester County Jail. His next court date is Aug. 20.