A 28-year-old man from Colby has been fined £650 for driving without reasonable consideration.
Dean John Wade, of Station Park, sent a postal admission and also had his licence endorsed with five points.
Prosecuting advocate Rebecca Cubbon told the court that a witness was driving down Richmond Hill in Braddan on April 11 at 8.25am.
They said that Wade was driving behind them, closing to around two or three feet behind, then dropping back.
The witness described the driving as tailgating and said that he was worried for his safety and that of his daughter who was in the car too.
He recorded the driving on his phone.
At the Quarterbridge the witness said that Wade started pulling out to the centre line as if he was going to overtake dangerously, then pulled alongside and made a rude hand gesture.
The court heard that Wade already has six points on his licence.
In written mitigation, Wade denied making any rude gesture and that he was at least eight feet away when he was driving behind the man.
Deputy High Bailiff James Brooks also ordered Wade to pay £50 prosecution costs which he will pay, along with the fine, within one month.