The owner of a vehicle in some instances bears liability. There are certain exceptions such as stolen vehicles or unauthorized use. This sounds like an unauthorized use but I don't see the other party stopping to send you notices. Notify your insurance company and they will defend you.
You may not be able to stop the plaintiff from attempting to sue you, unfortunately. However, because Sears was the party at fault, and seems to have admitted that fault in the past, then you need to take the appropriate steps to ensure Sears indemnifies you against any future loss.
At this point, I recommend contacting your auto insurance carrier and requesting they defend you in this action. If you run into difficulty from the carrier, then I suggest speaking with an attorney.
The foregoing is not legal advice, and nothing in the foregoing shall be deemed to create an attorney client relationship. If you feel you need to speak with an attorney regarding your issue, it is recommended that you contact an attorney with expertise in your area of inquiry. The information related above is purely for informational purposes, and should not be acted upon without speaking with qualified counsel familiar with you specific situation and the laws related thereto.
Notify your insurance carrier. The owner of the vehicle would typically be sued but Sears should indemnify you.
If you have additional questions, you can always contact a lawyer directly, whether myself or one of my colleagues. If you appreciate the time spent preparing this answer, kindly consider marking it BEST ANSWER or HELPFUL. Good luck to you.
Dean P. Murray
The Murray Law Firm
560 Sylvan Avenue
Englewood Cliffs, NJ 07632
Mr. Murray's response is NOT legal advice and does NOT create an attorney-client relationship. You should NOT rely on this response. Mr. Murray's response was generated without conducting a full inquiry as would occur during a face to face attorney-client consultation. It is likely that the response above may be made less accurate, or become entirely inaccurate, as you, i.e. the questioner, disclose additional facts that should only be discussed during a private consultation with an attorney. I strongly recommend that you consult an attorney who is licensed to practice law in your state (or, in the case of immigration law, and attorney in ANY state), whereupon all relevant facts will be discussed. All responses posted by Mr. Murray on Avvo.com are intended as general information for the education of the public, and not for any specific individual.