Depends what you want to do with it really
It's tight behind the dash, but there's room to run a cable along either of those routes
If you're just playing an iPod on random, I'd be tempted to run it into the glovebox (out through the hole that the interior light clips into, or round the changer slot) and you can drop the player safely in the ... can holder (or whatever the hell you're s'posed to use the round bit of the glovebox for)
If you take the changer or tray out, you should be able to push the lead from the radio slot, pull it across the back of the glovebox, and poke it into the footwell where you can tuck it round the trim for option 1
Option 2 is gonna mean taking the front facia off, so ashtray out (lots of Torx screws coming) two screws behind there, pull the bottom of the facia away and unplug the cig. lighter connection. Keep pulling and the trim will pop off some clips next to the A/C screen and two more either side of the radio (I think)
Should be able to tuck the lead down the side of the A/C unit, behind these clips and out somewhere below the ashtray slot
