i dont think they have install kits for these old cars. Youll have to do the wiring yourself. Had to do it when i put in a kenwood tape deck with 6 cd changer in the SD. Wasnt all that hard.
Also recently just done my 300D with a lanzar mp3 CD deck and 12' subs in bandpass box, Boss amp. Sold my MTX amp and subs and miss them, they hit hard! but my new setup hits harder