A4 2.0ltr s line vibration

[Josh764]

Hi all, I am new to this site.. Iv recently brought a 55 plate A4 2.0ltr s line and have had endless problems, but the most irritating and one I can't get to the bottom of is a vibration I get and it seems to go though the whole car when I accelerate. At low revs and speeds it seems fine and smooth, but if I accelerate a little harder around 2000 - 2500rpm I get a bad vibration only for a second or two then it's gone.. Has anyone else had this problem and can point me in the right direction..

Thank you all josh :)