It's a garage, for heaven's sake!! Many garages have no windows and there is no valid reason to punch through stucco (and with the accompanying expense involved) to add them. Unless the OP wants to..........but given their financial concerns of adding landscaping, that seems even more over the top. I'd look at it as a blank canvas against which to display something architectural.....like the Hollywood junipers (excellent suggestion, btw). If you can't afford them now, then I'd agree to wait and do nothing until you can. But a couple of junipers with a decent size to them is only a few hundred bucks....is that still out of reach?

I vote for cushions on the ledge. We find that they are great auxilliary seating when we entertain a group. Also one of the large sculptures or a bold black and white piece of art .

In the long run, I would change up the siding above the garage doors, as Tozmo suggested (I would probably wait until I was painting the exterior to tackle it, though). Add some horizontal trim to divide the two siding zone. Change the direction of the siding, or switch to a wide board-and-batten siding, or do wall shingles. Googling "mixed siding homes" turns up lots of examples. If you are into holiday decorating, you could reserve the space for a giant spider at Halloween, a huge wreath (or pair of wreaths) at Christmastime, and a flag for the 4th of July.

It looks amazing already, it really does!!! In front of the radiator you can do a bench. But other than that leave it empty. Add some art that speaks to you. What do you like? Big family photo? A painting? Maybe just a mural art with molding around it to frame it out... so many options. I’d also add some new pillows with more color. Black, Blue, brown leather....