Wouldn't moisture become an issue right up against the wall. I know in the winter when there cold and I turn a heater on you can feel the moisture on the walls.
You can feel moisture because the wall is sweating just like a cold beer can in the Summer.
Since you don't have your location listed, we can't tell where you are but sounds like you do get a cold winter.
I know you don't want to lose space with studding up the wall but I would still do something like that. I would tap-con furring to the wall vertically and along the top, at the bottom use a PT 1x4. Once that is done, glue some foam insulation in between the furring strips or duct tape will work temporarily. Then add some 7/16 OSB, plywood or drywall and screw it on but leave a small gap at the bottom so it is off the floor.
This will do several things for you,
Cover up that "ugly wall".
Provide you with a small bit of insulation, R3-R5, depending on which foam you choose.
Having that wall insulated, will help retain heat and create a thermal break from that block wall sucking heat out of your garage, this in turn saves you on heating costs.
Covering it with OSB, plywood or drywall will give you a place to hang some lightweight things or signs/banners. They are also softer if you accidently open a car door into them.
Using furring strips and 7/16" or 1/2" sheets, you will only lose 1 1/4" of floor space, well worth it for what you are gaining, IMHO.
