Yes, I used 190 and, before posting, I tried $this->attach($this, array('NOTIFIER_CART_ADD_CART_END')), too. Either way I don't get that notification. I subscribed to pretty much all of them. While I did add products, all I got was:

Got event: NOTIFIER_CART_GET_PRODUCTS_START
Got event: NOTIFIER_CART_GET_PRODUCTS_END
Got event: NOTIFIER_CART_COUNT_CONTENTS_START
Got event: NOTIFIER_CART_GET_QUANTITY_START
Got event: NOTIFIER_CART_GET_QUANTITY_END_QTY
Got event: NOTIFIER_CART_GET_QUANTITY_START
Got event: NOTIFIER_CART_GET_QUANTITY_END_QTY
Got event: NOTIFIER_CART_COUNT_CONTENTS_END
Got event: NOTIFIER_CART_SHOW_TOTAL_START
Got event: NOTIFIER_CART_SHOW_TOTAL_END
Got event: NOTIFIER_CART_GET_PRODUCTS_START
Got event: NOTIFIER_CART_GET_PRODUCTS_END
Got event: NOTIFIER_CART_COUNT_CONTENTS_START
Got event: NOTIFIER_CART_GET_QUANTITY_START
Got event: NOTIFIER_CART_GET_QUANTITY_END_QTY
Got event: NOTIFIER_CART_GET_QUANTITY_START
Got event: NOTIFIER_CART_GET_QUANTITY_END_QTY
Got event: NOTIFIER_CART_COUNT_CONTENTS_END
Got event: NOTIFIER_CART_COUNT_CONTENTS_START
Got event: NOTIFIER_CART_GET_QUANTITY_START
Got event: NOTIFIER_CART_GET_QUANTITY_END_QTY
Got event: NOTIFIER_CART_GET_QUANTITY_START
Got event: NOTIFIER_CART_GET_QUANTITY_END_QTY
Got event: NOTIFIER_CART_COUNT_CONTENTS_END
Got event: NOTIFIER_CART_COUNT_CONTENTS_START
Got event: NOTIFIER_CART_GET_QUANTITY_START
Got event: NOTIFIER_CART_GET_QUANTITY_END_QTY
Got event: NOTIFIER_CART_GET_QUANTITY_START
Got event: NOTIFIER_CART_GET_QUANTITY_END_QTY
Got event: NOTIFIER_CART_COUNT_CONTENTS_END
Got event: NOTIFIER_CART_COUNT_CONTENTS_START
Got event: NOTIFIER_CART_GET_QUANTITY_START
Got event: NOTIFIER_CART_GET_QUANTITY_END_QTY
Got event: NOTIFIER_CART_GET_QUANTITY_START
Got event: NOTIFIER_CART_GET_QUANTITY_END_QTY
Got event: NOTIFIER_CART_COUNT_CONTENTS_END

Anyway, using NOTIFIER_CART_COUNT_CONTENTS_END is sufficient for my workflow. But why am I not getting NOTIFIER_CART_ADD_CART_ is odd...