Audi A4 shakes BIG PROBLEM!

Hello,
firstly, sorry my englis is not very good, but I do my best .
So, I have Audi A4 1.9 66 kw
The problem is …I drive , course and speed are correct, but Car shakes(very much, that’s annoying, car pedaling moves back and forth…and you feel that the whole car “flick”. I thought that the fuel filter problem, but that’s changed now. Could it be the transmission pillow problem? Or drive shaft?

Thank you !!

what year? how many miles (or km) ?

66 kW = 88 HP. Is that the engine size?

^
Additionally…
Is the car still under warranty?
Is the Check Engine light illuminated?
Has the car been maintained at least as well as the manufacturer specifies?

It would be helpful to know if the vehicle shakes at idle or when moving (or both). Also is the shake speed related? Does it appear in the 50 to 70 mph range (80 kph to 115 kph)?

If this happens only when you’re moving, there can be any number of causes. However, please check right away that your lug nuts (that hold your wheels on the car) are all tight. If one wheel is loose, this would be a very dangerous situation.

And please don’t feel reluctant because of your English. You’re doing fine. Do your best to tell us what’s wrong and I promise we’ll do our best to try to help.