i have a 2005 subaru impreza rs, my mate says get a pod filter as it gives extra horsepower and better sound but i have read forums that tell me different. what do use reccomend?

Don't bother. The H4 motor is torquey at current air flow, and NOT starved for air at higher revs (where it's not that happy anyway). We've tried all manner of CAI and fancy filters to no avail. You're better off putting money into great V or Z-rated 17" rubber to finesse this nice Subie. Iridiums are nice too. If your '05 has the '06 VVT motor you'll find it's already optimized for timing at all revs, but even the 2000-2005 older version is what it is, not benefitting from additional airflow. Have fun; the only way to make it marginally faster is to trade it for an '06-'07!