A senior source said: "He is covered in cuts and bruises but he will be OK. Gardai want to question him for sure.
"High-grade explosives were used in this attack, which could have caused death or very serious injuries."
Detectives are investigating whether the attack is linked to an alleged "love triangle".
The owner of the vehicle is not involved in crime but may have fallen foul of a south inner city criminal grouping described as "particularly nasty and dangerous".
Meanwhile, the Herald has discovered that the injured bomber fled in the direction of New Street and Clanbrassil Street, bumping into parked cars and lamp-posts because he was blinded by the blast.
Bleeding from his wounds, the man wrapped part of his clothing around his arm and hand and clutched it to the side of his head which was "roaring red", according to witnesses.
"He stopped at one stage and leaned against a taxi that he had bumped into, his head and face were in bits, I thought it was all blood, but it looked like his skin had been stripped from his head," said one local man.
"He had something wrapped around his hand and arm, and was holding his arm to his head. He was in ribbons. Surely he had to go to a hospital."
The man flagged down a taxi on New Street or Clanbrassil Street, going in the direction of St Patrick's Cathedral, which brought him to hospital.
HE SUFFERED SEVERE BUT NOT LIFE THREATENING INJURIES TO HIS FACE AND UPPER BODY.
Armed officers were at the hospital last night.
Gardai later took the taxi that the man had fallen against for a forensic examination in the belief that he had left handprints and bloodstains on it.
They also retrieved CCTV from local pubs and businesses.
The army bomb squad was called to the scene after locals near the old Meath Hospital reported a massive bang and seeing a vehicle on fire at around 10.50pm on Sunday.