Civic EG

okay so when i bought my 1993 civic si, it didnt come with a deck, then a few days ago i relized after instaling my deck the music was only comming from the front, so i instaled my pionneer 6x9s directly to the rear speaker wires, there really loud, but what problems could this cause with the car? they run perfectly fine, and run as if they were amplified? so should i leave it or what could happen?

If you like the sound and are happy with it, leave it be and roll with it. Did you have to cut the rear deck to fit the 6x9's?

If they're overly loud check the settings on your head unit. Maybe the fade(front/rear) setting isn't adjusted right. Personally I like to adjust mine a little more to the front than back because the rear speakers are usually intended for fill, with the majority of your sound(vocals, highs, some mid range) coming from the front and the mids, lows and background sounds coming from the rear.