I put the mustang into storage late last november or early december. I changed the oil, i added stabile to the gas and check all fluid levels when it went into storage. I had tried to start the car when i could over winter and check fluid levels as well. I brought it out of storage and all seemed good. I went through a tank of gas, and found my car having a slight rough idle and hesitation. I took it home and check the ignition( plugs wires and coil pack). found one plug to be broken. i bought a new plug replaced it. car ran better. well went through another tank of gas. and found the car to run as it did, rough idle. I bought all new plugs wired and new oil aswell. Car needed the oil change since it has been 4-5 months. I replaced the plugs and wires, and no change. I also swapped the coil pack with the stock one, and still no change. cleaned the IAT sensor. No the idle is pretty rough. as in when the car is sitting and idling, the whole car shakes. Kinda like a harley lol. I hate it. the bad vibration happened around 1000 to 1400 rpm. The vibration is shaking the dash, steering wheel, and my seat. My uncle had me put the car in reverse and drive, and watched to see if the motor mounts went bad but it seems to be ok.... Any other ideas.