6th gen and most ppl on this board go by what generation accord instead of stating the yrs cuz its much quicker and simpler.
like this http://www.morningz.com/mz/integra/audio.asp
on that site thr are generation 6 DIY, if you searched in google, 1999 accord stereo help, then this wouldnt have came up.
oh and keep that DIY, it might come in handy.