Overlays for you taillights can be ordered from bluebatmobile.you can send him an email at firstname.lastname@example.org He may take a while to reply. His work can be seen here Pictures by BlueBatmobile2005 - Photobucket
or order for sedan from http://www.premiumautostyling.com/20...4_3562816.aspx
for hatch from http://www.premiumautostyling.com/20...4_3787533.aspx
Alternatively you can also paint your tailights in different configurations.
Instructions DIY: 2009 wrx tail light mod (only 10 dollars!) - NASIOC
I used http://www.amazon.com/Dupli-Color-MC.../dp/B000994BUM & http://www.amazon.com/Rust-Oleum-770.../dp/B0010NY95S