Your car's dash just got a tad bit more interesting with the introduction of Pandora music streaming in Pioneer's latest navigation unit. The double-DIN in-dash device exploits your iPhone's cellular connection to glean tunes from the ether and comes with a 6.1-inch display, Bluetooth, 3D video accelerator, and 4GB of built-in memory expandable by MicroSD. Coming out in March for $1,200, this is slated to be a direct challenge to satellite and old school radio services, and for more on the greater market impact of its introduction, you can see the WSJ coverage below. For the full specs of this new flagship devic