The lower rear bushes are very much prone to wear, even on a low miler like yours. Its almost certainly those. The upper rear bushes aren't so bad though.
#2 4D0 505 171L is in two pieces and is pressed in to the hub. Dealer only.
#4 4D0 505 171H is also in two pieces and is pressed in to the lower arm front. Also dealer only.
#5 is a single piece pressed in to the lower arm rear. This can be bought aftermarket from Febi or Meyle.
I would recommend you also check the condition of the rear track control arm and it's associated eccentric bolt at the same time, as these are almost always seized solid. You'll need a rear wheel alignment after changing the bushes, and if the TCA is seized the alignment isn't possible so it has to be cut out and replaced.
The number for that is 4D0 501 529H, also available from Meyle or Febi. The eccentric bolt is no longer available but the A6 C5 bolt can be used instead 8E0 501 387B.
Its about £350 in parts if you have to do the TCA as well, and a day to change it all if you have access to a press.