i just bought a rear cusco SB and some helix endlinks, i know this will improve the handling of my car but is it nessesary to do the front sway bar too on an 2004 sti?

 

There is benefits to be had with upgrading your front bar too, but a rear bar alone will certainly improve the handling. I've done both just a rear bar upgrade on my RS, and have both bars upgraded on my WRX. Upgrades on both cars certainly improved handling (and reduced understeer).

 

hey thanks! i think i'm gonna run it like it is for a while and then get the front later