If I had a choice between a new z06 or an RS4..........
To be honest, If I had a family to get around and I still wanted something with balls for a daily driver then I would buy one. AND just upgrade the turbo setup, and do a full Remus 3' exaust + chip/ K/N filter on an Audi S4 and you can be doing better then an RS4 for a half of the cost.
AND IF you are going to buy an AUDI do it right !!!!!
http://www.fourtitude.com/news/publish/ ... 1827.shtml
S8 v10 goodness. !!!!