If it shakes all the time it is a tire/wheel problem. If it only shakes when braking then it is a brake problem.
Motor is idling rough.
who is this and then i will tell you
Most likely warped brake discs
Transmission mounts are bad
maybe the car need to be linged up n check the power steering.
Tire out of balance, loose lug nuts, worn wheel bearing, or bent wheel.
Check your power steering fliud, if it is low this could cause the vibration you are feeling.
Not surprisingly, it depends, if the steering wheel vibrates all the time, no. IT could be a whole bunch of things. If it just vibrates at a certain speed range, roughly 50 to 70 mph, it is probably the tracking on your tires (or at least that's worth checking as it is a cheap procedure). Either way, if it makes you feel unsafe whilst driving the car, then don't drive it.
Bad CV joint? How about a bad steering box?
sitting and idling ?possible bad engine or trans mounthave them inspected
Losse wheel, worn bearing, or more than likely, a worn CV joint.
Sounds like you have a bad tire with belt damage.