I've purchased parts from Morningside Nissan before, and their parts department seems fairly knowledgeable and helpful on the phone. As with most dealerships you have to purchase the item in full before they can order it for you. Sometimes with other dealerships that know you, they will order the part regardless if you're a regular customer. Morningside is more by the book and require full payment up front before the orders can be made.
As with most dealerships the mark up is fairly high here and the wait time for parts can be as long as a few weeks to a month. They don't offer any kind of discount pricing as well for regular or returning customers, as with other dealerships.
Simply due to proximity and price, I have move to Scarborough Nissan to purchase parts I require. If Morningside was willing to order parts over the phone or without full payment up front I would be willing to come back. Also having a customer loyalty program as with other dealerships would be helpful.