What model, engine, trans etc.; what have you fixed in the past? If you can take a video with your phone; you might post it up here or on youtube. Maybe we can get a sense of what the problem is! What is the history of the car; how many miles, any work done to it lately and how is it running/driving? Help us; to help you! We need more info and in depth description of the problem!
Please give us; more of a more detailed description of how it is running. If it is shaking; low power, idles very rough and the check engine light is on or flashing, MANY times it is a bad coil pack. They can often fail; especially, on the older ones but the latest revised part, is allot better. There was a recall on these; did you ever have them done at your VW dealer? Do you have access to a scan tool? There should be some trouble codes; if a coil is bad or the engine is running poorly.If you get a trouble code for a specific cylinder misfire; you can change the location of the coil pack and if the code follows, to the new location.... it is usually a bad coil. I recommend; you get a oem Bremi coil pack from your local VW dealer. They are not expensive and guarantees you get the latest revised part. The genuine VW coils; perform the best and last the longest, do not buy aftermarket coils from your typical auto parts store. Let us know; how you think, the car is running and if you have, any trouble codes.