Before you report this claim to your insurance company, try the following:

• Take Photos: Take a picture of the scene and a close-up of your damage. If there are other cars parked around yours, make sure the photo captures the other vehicles as well.
• What's your Collision Deductible: Look up the deductible for your Collision coverage (assuming you have Collision Insurance)
• Get an Estimate: Stop by your favorite local auto body shop and ask them to provide you with an estimate of repairs. You now know what amount is a reasonable settlement with the other insurance company or the other party directly.
• Estimate Less than Deductible: If the amount of the estimate is near the same or less than your deductible:
• The other party left you a note with your name and phone number. That's a good sign that they are willing to make things right.
• You are much better off initially seeking payment from the other party's insurance.
• The fact that this is a not-at-fault accident does not guarantee your rates won't be affected. Many auto insurance rating plans will look at claims frequency regardless of fault.
• Even if the party that struck your vehicle is willing to take responsibility for the loss, personally obtain their insurance company, policy number, and agency or company contact information.
• If they choose to pay personally, accept only cash payment. If they hedge, you still have their insurance information to seek compensation from their carrier.
• Estimate More than Deductible: If the amount is significantly greater than your deductible:
• It would be best to pursue this with the other party's insurance company. You were parked, and the vehicle was unattended. There will not be a question of fault.
• If the claims process with the other party goes awry, you can change gears and place a claim under your collision coverage.

In a claim where your car is parked and unattended, and the other person is willing to work with you to make things right, it makes sense to pursue coverage under their insurance first before submitting the claim to your insurance company and having that activity reflected in your claims history.

However, if things go south with the other party, you should quickly obtain a police report and submit the claim to your insurance carrier.