Nah, wasn't intentional - it was one of those quick shots where all I really did was set the shutter to 30sec, attached a suction-cap mount to the camera, and attached it to the windscreen of my mate's van which was parked in the driveway. I couldn't get a reading for the autofocus to zoom on, and because of where and how the camera was mounted, I couldn't manually focus either...
It was a bit of a rushed experimental photo, as we were about to jump in the van to head home, so I didn't really make the time to set a manual focus/exposure point, and I used the flash simply to help the camera get somewhere to focus on. Next time I'll either set the focus point (or manually focus if possible) and spend a bit more time on it.
I mainly just took the shot because of the clouds in the sky, shame they weren't in a more interesting pattern...