Tomato sauce depth of flavor question

I'm wondering if anyone has any suggestions for adding depth of flavor to a tomato sauce. I made some tonight from scratch and get alright tomato flavor, and enough acid, but I'm not getting the real "tomato" depth of flavor.

I almost feel like it needs some demi-glace to really bring out that depth, but I don't have any and am not likely to come across any in the next hour or so.

Any suggestions?

I've added enough balsamic, salt, pepper, and some tomato paste, as well as the usual suspects- garlic, shallots, wine.