If your Impreza is a manual it will be on the drivers side, if it's an auto it will be on the passenger side. They are both close to the firewall, both will have a yellow handle( the manual could be bare metal ). The auto dipstick sits up much higher than the other one, and you may have move a big fat harness aside to see the manual dipstick, it's well hidden.
The 2001 Subaru all back transmission dipstick is located behind the engine, in the engine compartment. The transmission dipstick should have a yellow handle.
The 2006 Subaru Impreza has a 5-speed manual.
The 2004 Subaru Impreza has a 5-speed manual.
The 2008 Subaru Impreza has a 5-speed manual.
The 2014 Subaru Impreza has a 5-speed manual.
The 2012 Subaru Impreza has a 5-speed manual.
The 2002 Subaru Impreza has a 5-speed manual.
The 2010 Subaru Impreza has a 5-speed manual.
The 2009 Subaru Impreza has a 5-speed manual.
The 2001 Subaru Impreza has a 5-speed manual.
The 2013 Subaru Impreza has a 5-speed manual.
The 2007 Subaru Impreza has a 5-speed manual.