Unfortunately, your liability has nothing to do with whether or not you're aware of what you've done, or how minor the damage may be. Therefore, the fact that there was hardly any impact is irrelevant. You either hit the car or you didn't hit it ... and if you hit it, then you're responsible for fixing the resulting damage.
I'm also sorry to say that the fact that the other car was parked improperly is also likely irrelevant. A judge would probably rule that it is your responsibility to make certain that your path is clear. In other words, it is generally no excuse to hit something just because you didn't expect it to be there.
Last, the fact that you have a flawless driving record, and the fact that it happened on your b-day are also irrelevant. Those could possibly be helpful factors if you're dealing with a speeding ticket or parking ticket
, where it would just be another payment to the city/county. But in this case you're dealing with damage to another person's property. If you did in fact cause the damage, how could a judge possibly tell the victim: "I'm sorry that your car was damaged, but I'm not going to hold the negligent driver liable since it was his b-day and he's never gotten a ticket. You're going to have to pay for the repairs yourself." Surely you'd agree that such a ruling would be an injustice.
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