LG Fusic / LX-550

i'm considering buying this phone, but would
like to know something about the experience of
those who have been using it for playing mp3s.

the reviews i've read list the "talk" and
"standby" battery life, all you need to know
about most phones. but what effect have you
seen on battery life when playing mp3s? if i
load the phone with podcasts and take it on a
six hour drive using the fm transmitter, will
i be able to make a phone call when i get to
my destination? will i be scrambling to find
an electrical outlet to recharge it for a few
hours? how does the speed of discharge when
listening to audio seem to compare to the
speed when making calls?

thanks for any insights you can share!