Once we challenged the all-new 2008 BMW M3 and its new V8 against the elegant, surprisingly capable, all-wheel-drive Audi S5 and its V8, we got a few surprises on the way to an inevitable conclusion.
Source: Edmunds - Inside Line
Original Story: http://www.edmunds.com/insideline/do/Drives/Comparos/articleId=125265
Without reading edmunds.com
Without reading edmunds.com post I'm going to go with Audi. Design and performance I think Audi have an edge. Autopartswarehouse.com know some points to check to get good performance parts.