The Youth Court heard that the teenager, who cannot be named due to his age, took a car in Patriotic Street car park in the early hours of 19 August.
He drove the vehicle into a wall in the car park and left it there.
The teenager also took a Range Rover from the Waterfront on 9 October.
Advocate Sarah Dale, defending, pointed out that the teenager pleaded guilty to taking and driving away vehicles without their owners’ permission, and driving without insurance.
“He is aware that this has got to stop,” she said.
The boy added: “It was that adrenalin rush.”
But the Magistrate, Bridget Shaw, replied: “That is no excuse, is it?”
She said the offence was “serious enough for custody” because of the risk posed to the public, but had instead decided to bind him over for a year.
She also banned him from driving for five years, leaving him unable to take a driving test until the ban has elapsed.