Not just the brand, but type of spray: stream? Fog? Spray?
Just like with your sidearm, test it on a cardboard target at varying distances.
I keep a stream in my car a large cannister in the door pocket driver side. I leave my door cracked open for quick access at the gas station. Larger can serves as a bludgeon as well in a pinch.
The stream I carry from personal experience. When I was in college many years ago, I took an ass beating and 8 stitches from a split lip when some idiot I didn't know mistook my idenity. He just came up started pummeling me from out of the blue. It all started when he challenged me to "get out of the car bitch, I am gonna beat your ass" well all I remember is the seeing the fist as he was drawing back and tasting the salty blood. Can you say eye opener. Long story short, I kept thinking back on it and how I could have gotten out of the vehicle before being hit several times or having the door slammed on me as I tried to exit. The stream gives decent range and is less likely to blow back in your face.
Have Fun