Clearly it is a sign to get your car thoroughly checked by a good mechanic. It can be caused by any number of causes.---usually lack of maintenance or parts that have gone bad. Good luck.
I have a 2003 ford mustang base model automatic rear wheel drive.In the mornings when i start my car and come to a stop i hear a loud rumble and vibration in my car,it only does it when i come to a stop.As the day goes on the rumble and vibration goes away,any1 know what this might be?