Dear [Manager's Name], I hope you are doing well. I recently brought my car to your garage for repairs due to issues with the engine misfiring. While I appreciated the service at the time, I regret to inform you that the problem persists even after the repair. Specifically, the engine still misfires when I start the car, and I continue to experience difficulty accelerating. These were the same issues I had hoped would be resolved during the repair. Unfortunately, the repair has not improved the car’s performance as expected. I would appreciate it if you could have a closer look at my car to ensure the issue is properly addressed. I would prefer this follow-up service to be done at no additional charge, as the initial repair did not resolve the problem. Please let me know when I can bring the car in again for further inspection. Thank you for your attention to this matter. Sincerely, [Your Name]