The last feature film of Orson Welles was F Is For Fake — a weird, pseudo documentary about famous art forger Elmyr de Hory and biographer/not-biographer Clifford Irving. The film is confusing because it includes real people and situations, as well as fake ones, as well as real people (like Clifford Irving) who were later found out to be fakes. It's considered a film essay, and though viewers at the time were turned off much of the same techniques are commonly used in television and film now (Curb Your Enthusiasm and The Office). Art's not always appreciated in its time, so the car bomb art wasn't for everyone, but TramplaOnline gets it.
To all the haters the naysayers and the confused/angered, if the artist had blown up the car, it would have nullified the meaning behind the display of it. Al Qaeda/insurgents/whatever weren't out to create an art piece when they blew the car up, they were out to kill and frighten innocent people into cowering to their extreme beliefs, or destroy them for not believing as they do. The artist took that destroyed car and turned it into something more meaningful, even if all he did was bring it into a museum, to bring a focus on the brutality of modern warfare. It isn't to glorify terrorism, it's to bring attention to this form of warfare's (terrorism's) brutality. Possibly, as a sort of counter-point to the way that war could be seen by some (outside the military, of course) outside-the-know that with guided drones, warfare has gotten sterile and mechanical.
This form of art is called "found object art" or simply "found object." Some may not appreciate it, but it's hardly a new form of art. Ever heard of Duchamp's Fountain? Rauschenberg's Monogram? Also, art isn't really about defining a "truth." It's more about creating and asking questions, much more so than answering them. So, if you don't get it, or you're offended by it, there's nothing wrong with that and there's nothing wrong with you. Those are just some of the reactions that artwork can provoke. Art isn't judged as being successful or unsuccessful based on how many people like it, or think it's pretty. It's got much more to do with meaning and concept than that, evoking an opinion, creating a reaction. On the contrary, if all anyone had to say about it was that it was "nice," you'd probably be safe in assuming that it was not a successful piece.
Full disclosure - I have a degree in art and I also took a very challenging class in international terrorism when I was in college, which I earned an "A" in. But, what the heck do I know?
Someone's really happy about themselves, eh?