Just wonderin' if I could hook up an amp w/o buying a deck.

 

most stock decks do not have RCA jacks.. so probably your 99 Acoord tape/cd deck does not have RCA outputs.. if you really don't want to replace your head unit.. you can get line level converters that tap into your speaker wires and then output RCA's for you to connect to your amp... it costs about $20... sound quality wont be top notch.. but it will enable you to use your stock unit..

I replaced my honda deck the first week I bought my car Lolz