Security forces said he was lucky to escape with his life after he spotted a bomb underneath the driver's seat inside his car on January 5.
The soldier from Britain had been visiting a girlfriend when dissident republicans opposed to the peace process opened the door of his UK-registered Vauxhall Astra and slipped the device beneath the seat.
Three men, aged 43, 40 and 30, and a 41-year-old woman were arrested in north Belfast on Friday.
Police said they were taken to Antrim Serious Crime Suite where they are being questioned.
Officers also searched nine properties in the area.
The dissident group Oglaigh na hEireann claimed it was responsible for the murder bid.
The car had been parked in a housing estate off the Ligoneil Road in a nationalist area of the city, but police said they did not know when or where the bomb was planted.
It is understood the soldier noticed a wire connected to the driver's seatbelt and then discovered the device below the seat.