Do I have a claim?

Do not cash the check. Get proper medical diagnosis and care. If you are injured, retain a WA personal injury attorney ASAP. Remember, insurance companies lowball accident victims for a living.

You have a claim and three years in which to file it if you are over the age of 18. There are a lot of factors that go into determining the value of a claim, but the basics are vehicle damage, type(s) of injuries, medical bill amounts, length of treatment, type of treatment, medications, lost wages, loss of consortium and other property damage.
You should call around and speak with an experienced PI attorney. Before doing personal injury work, I did insurance defense, which means I worked hard at making sure that people in your position got paid as little as possible. Insurance companies aren't in business to pay money out, so they will work you over every chance they get. The above attorney's answer is correct. Don't cash the check, and do call an experienced attorney. I think any capable attorney will come to you after hours or over the weekend to answer your questions.
Good Luck!

Although you have a claim for personal injury, it is not likely to have much value because you did not see a doctor or get treatment. Because you received a diminished value check it sounds as if your vehicle was repaired. You might talk with a repair shop with knowledge regarding diminished value or an attorney who handles diminished value claims. Best wishes.

you do have a claim. so does your passenger.

Your damages will be fairly low since you just have soft tissue injury. Are you going to a chiropractor or seeking any other medical treatment? Did you suffer wage loss as a result of the incident? Was there a policy report taken and did you report this to your insurance? Your passenger and you both have a claim. I would not cash the check yet - call an attorney before doing so because it is very likely that there's a waiver clause in there stating that when you cash your check, you release them of any and all liability or claims as a result of the incident. Many attorneys, like myself, give free initial consultations. Call an experienced attorney for more advice.

You have a negligence claim until 3 years from the date of the accident at which time the limitation period will expire and your claim will be barred by the statute of limitations. In your case it appears that your main damages are property damages, although you and your passenger may have a personal injury claim worth pursuing. You should consult an attorney as soon as possible.
This answer is not legal advice and is for general informational and/or educational purposes only. No attorney-client relationship is formed between you and Sean B. Malcolm, an attorney licensed in Washington. For more information, see the Avvo.com terms and conditions of use, which are incorporated by reference herein, and www.kirklandtriallawyer.com.