That's what racing legend Al Unser Jr. told a police officer during a DUI arrest in May -- right after he drunkenly fell down a hill in a wild arrest captured on video.

Unser -- who won the Indy 500 twice -- was pulled over in Avon, Indiana on May 20 when an officer saw him speeding and swerving all over the highway around 1:12 AM.

During the stop, the 57-year-old gets out of his car barefoot and smoking a cigarette -- and the officer immediately notices the smell of booze from both Unser and the car. Unser claims he reeks because he was "kissing on a girl" just 5 minutes before.

As the officer asks Unser to walk toward the sidewalk and out of the street, the racing legend stumbles over a curb and falls down an embankment.

The officer helps Unser up -- but Al is pissed off and accuses the cop of "hunting" for him that night ... just so he could pull over a famous person.

Once he gets cuffed and put in the cruiser, Al really gets mad -- dropping F-bomb after F-bomb after F-bomb ... while taunting the cop for the way he's driving.

At one point, a rambling, babbling Unser makes a comment about "shooting" cops -- to which the officer replies, "Are you saying you want to shoot cops?"

Unser sort of explains that he meant the cops were TREATING him like someone who wants to shoot cops.

When the officer informs Unser he's going to jail for DUI, the racing legend begins to LAUGH MANIACALLY ... and then says, "Thank you very much you motherf**ker!"

Unser was eventually charged with DUI, improper lane change and speeding and was facing up to a year behind bars. But, he cut a sweet deal with prosecutors in August where he pled guilty to DUI and the remaining charges were dropped.

He was sentenced to 363 days of probation, 480 hours of community service and he must complete a victim impact panel, where he discusses the perils of drunk driving.

Al's driver's license was also suspended for a year from the date of the arrest.

The craziest part about the whole incident ... the arresting officer told Unser at the start of the arrest that he was a RACING FAN and seemed like he wanted to help Unser, not drop the hammer on him.

This wasn't Al's first DUI -- he was arrested in 2007 and 2011 and has talked publicly about his battles with alcohol.