it all depends... u had subs in my 318 (they still are in it, i just dont realy drive teh 318 anymore) and liked it for a while... they fit pretty good but still moved a little bit during aggressive driving... once i got the 325 i said i wasnt going to put them back in. In fact i havent done anything to the 325 sound wise yet... eventaully i might put some 6x9's in there and some better quality speakers but i dont think ill ever go back to subs again... The only way i would ever do it again would be if it was one 10 in a small box that i could unplug and take out whenever i went to the track, or on a drive somewhere just because brien is right.... you do notice a difference on the low end
David