添加Product Type并不是新建文件就可以的，同时还需要配合数据库。可以参考product_music。不过通常一个Product Type会涉及到这些目录下的文件，以product_music为例：
./admin/product_music.php
./admin/includes/languages/english/product_music.php
./admin/includes/languages/english/extra_definitions/product_music.php
./admin/includes/boxes/extra_boxes/product_music_extras_dhtml.php
./admin/includes/modules/product_music
./admin/includes/functions/extra_functions/product_music_functions.php
./includes/languages/english/product_music_info.php
./includes/languages/english/extra_definitions/product_music.php
./includes/modules/pages/product_music_info
./includes/templates/template_default/templates/tpl_product_music_info_display.php
./includes/templates/custom_template/templates/tpl_product_music_info_display.php