Well, not really a car accident in normal terms between two or more cars, but first time where I was the driver and damage was inflicted to my vehicle.
Scenario: I was driving on Interstate 270 (St Louis) going home. It was night (about 8:30pm), cloudy, and there was some distant lightning. I was driving my family's van home from a small group in Creve Coeur, MO and I was the only one in the vehicle. There weren't very many cars around and I was going perhaps 60 to 65 mph. Interstate is five lanes wide and I was one lane away from the far left lane.
Incident: I looked up and saw a dark object swirling through the air towards the left front roof pillar of the van. I didn't have any time to react and just barely managed to pull right a little bit, but the object smashed into the front left side of the van. My blood pressure jolted a bit and I think I uttered something under my breath in reaction and I hit the brakes slowing to about 50 as I looked into the side mirror. The UFO (logical definition) hit the ground and rolled (yes, it was circular in shape) towards the lefthand shoulder. It looked like a hubcap.
Reaction/aftermath: At first I didn't really know what I should do. There was still about six miles left until my exit, but I wasn't about to pull over on the interstate. I continued driving, took my exit, and parked in a commuter parking lot and got out to assess the situation. I was worried that the object could've hit the tire and would prevent me from safely getting home (still 20+ miles away). When I got out, there were fairly substantial dents to the left front fender and the left wraparound portion of the bumper. I uttered something else and decided to call my dad. I just paced up and down talking to him describing the incident and the damage. After I hung up, I drove home.
Damage:

What I Think Happened: A driver in the oncoming highway lanes lost a hubcap while in motion. The hubcap hit the banked side of the wall, jumped over, and wound up flying through the air towards oncoming traffic. I was just in the wrong place at the wrong time. It could've been much worse. Had that thing hit the windshield or the driver side window, I might not be posting this.