I think the OP did fine. There's no telling what the bad guy was capable of or what weapons he had hidden on him. Who knows, he might have become more enraged when the OP didn't get out of the car or when he couldn't break the window. If the bad guy had broken the windown and then landed a hard shot to the temple or jaw, the OP is knocked out or worse.
It's easy to judge behind our computer screens, but we weren't there. Just reading the story got my heart racing a bit. I'm in my early 40's but have certain medical issues that certainly make me think twice about getting even into a fist fight. Things like high blood pressure, asthma, my dominant arm has had recent issues with tendinitis and degenerative changes, not having perfect vision, etc. All things that would put me at a disadvantage and yes, possibly create a disparity in force. I have no MMA training, didn't wrestle in high school, and go out of my way to avoid fights or confrontations.