EITHER take out your glovebox & see if there's a rubber bung in the bulkhead you can pull out & feed your cable through; not sure if there is on on an Eclipse, but there's usually a spare hole somewhere on most cars due to the LHD/RHD compatibility of the chassis for overseas use
OR You may have to do it the harder way; pick a nice empty spot on your bulkhead [check the inside too to make sure there are no wires etc in the way !] and drill a hole sufficiently large to feed the cable through.
Either way, you'll also need to find a rubber grommet to fitround your wire where it passes thru the bulkhead, so stop the metal from chafing through the cable insulation. I managed to use the hole for the LHD steering column to feed my live cable through, so I just cut a hole in the bung that was there & used that to reseal the hole around my cable
Obviously, if you're forced to drill a hole [I'd ALWAYS use any changes to the standard chassis/trims of a car as a last resort] you'll have to go round your local DIY places and find a suitably sized rubber to fill yer hole