Gearboxes

Hello,
I would like to introduce myself. my audio
==References== I bought three weeks.
The Audi A 8 is an Audi A 8 and the Audi A 8 is an Audi A 8. V8 year built 12.1996
40.2 quattro with 299 ps.
approx. one week after the purchase of this magnificent piece
during the drive (automatic) I noticed the
==References== 1000 turns slightly vibrates as if it turns up
and tried to turn back down and up again.
only at a higher speed it stops jerking.
It does not always happen, however, is so ca. occurred within the three weeks 6-7 times!

now I hope that you can help me further here, because I want to
driving with this car on holiday and would like to know what could possibly come to me!

greetings
birgull