The Flashback Forum (h/t Gudmundson) identifies the owner of the car as Taimour Abdulwahab (28), who lived in Tranås (Jönköping county). Taimour's last name is Al-Abdaly and he used this picture for his Facebook profile.
Swedish newspaper Expressen reports that police suspect the car owner is the suicide bomber (SE).
According to Gudmundson, the name indicates he's from Amman, Jordan, and according to his Facebook profile, he visited the country last March. The "Islamic Caliphate State" and al-Qaeda ideologue Sheikh Abu Muhammad al Maqdisi are listed as his favorites, and he's posted clips from Chechnya and Iraq.
Gudmundson points out that though this attack was the first on Swedish soil, this is the 7th suicide bomber from Sweden, and the third to succeed in exploding.
SPIEGEL ONLINE identifies the suicide bomber as a young Iraqi who was very active on various social networks and spoke against the wars in Iraq and Afghanistan.
Taimour was looking for a second wife on Muslim.com:
"I was born in Baghdad, Iraq. We moved to Sweden in 1992. I moved to UK 2001 to study. I have Bacholar degree in physical therapy. Iam married sence 2004 and have 2 girls. One is 3.6 and the second is 1.6 years old. I want to get married again, and would like to have a BIG family. My wife agreed to this. Iam looking for a practecing muslim, sunni, love children and wants to please Allah before me. Ecenomically, am ok. I cant say am rich, but alhamdolillah not poor. When I have extra money I give for the needy. Which aswell is importat that you not going to mind that.
In the future, am looking for to move to a arabic country and settle down there...
Hope you are a strong beliver and striving for jannah [ed: Paradise], if you are. Get in touch please, wsalamo alekom"
DN.se reports (SE) that the police assume that the attacker detonated the car, which was filled with gas canisters, in order to attract police and emergency personnel.
A witness named Pascal told DN.se that he heard the explosion and saw smoke coming from Bryggargatan street. He ran 30 meters down the road and around the corner and saw a badly injured 26-26 year old man lying on his back.
Pascal is a trained medic and tried to save the man: "When I arrived he heaved his chest a few times, but had no pulse. I removed a Palestinian scarf from his face to free his airways and attempted CPR, but it was too late."
Pascal says the man was seriously wounded in his stomach. Next to him he saw a two-meter pipe and a shoulder bag. It looked as though something exploded in his stomach. He had no injuries to his face or elsewhere in his body, and the shop windows around him were whole.
Pascal: "My first thought was that the man was a terrorist."
Expressen reports that police suspect the bomber blew up too early. He was heading for a street filled with Christmas shoppers. Police are now looking for a person seen talking to the bomber just before he exploded.
Update: Aftonbladet reports that the suicide bomber signed the email (SE) sent just minutes before the explosion with his own name. See here for more on the email.
Update 2: Fixed typos.
Update 3: Norwegian paper Dagbladet reports that the name on the email is the car owner's name. (NO)
In late November he wrote on his Facebook profile: "God take my life when you're happy with me. God grant me honesty in words and deeds. God I dedicate all my acts to you. God keep me from falsehood."
The man's father says the bomber was his only son and that the family is in shock. "He was home on Friday, woke up Saturday morning and went off. He didn't say where he was going. Had I known where he was going, I would have told about it. The whole family is in shock and want to find out what happened."
Update 4: The Swedish Security Service said they are investigating this as a terrorist attack (SE) and that it can happen that they miss things.
Update 5: An man was arrested today at about 11:30AM after he waved an axe menacingly by the Prime Minister's office. He then jumped into his car and drove off. He was intercepted by the police, who arrested him with weapons drawn.
The suicide bomber's letter urged Muslims to "go forward with whatever you have, even if it is a knife, and I know you have more then a knife"