Dreaming about deceased loved ones, such as your grandmother and mother, often signifies a connection to their memories and the values they imparted. The setting of a big house suggests a sense of security and family legacy, indicating that you may be reflecting on your roots and the importance of family in your life.

Your grandmother's advice to pay attention to the special things could symbolize the need to focus on what truly matters in your life, perhaps encouraging you to cherish significant moments and relationships. The urgency to fix your nails in the car suggests that you might be feeling pressure to present yourself well or to meet certain expectations, either from yourself or from societal standards.

Overall, this dream could be urging you to prioritize what is truly important to you and to take care of yourself, both physically and emotionally. Consider reflecting on what "special things" mean to you in your waking life and how you can embrace them. It may also be a reminder to honor the legacies of your loved ones by living authentically and valuing the moments that bring you joy.