"Die Hard" in London?

Anyone else suspicious about the un-ignited car bombs in London yesterday? It occurs to me that these two cars were unnecessarily suspicious and the whole thing seems really sloppy. Could this be some sort of diversion to throw the police off of something less obvious but more nefarious, a la "Die Hard: With a Vengeance," where Jeremy Irons' character plants bombs around NY and plays sends McClane on riddle-errands to distract the police from his real goal (to steal tons of gold from the unprotected financial district)? I hope I'm not on to something.

Postscript (7/2/07): Apparently I was not on to something. Since this posting there have been a couple other automobile-related incidents, (including the Glasgow Airport attempted firebombing) all of which were utter failures. I originally thought they were failures because they were meant to be diversions, but it turns out it was because they were executed by inept doctors instead of seasoned Al-Qaeda operatives. Congrats to the British law enforcement who've been arresting these guys left and right. Continued success and good luck!