The Audi Club International (ACI) hosted a quattro meeting from 5 to 7 August 2005 in Ingolstadt to mark the anniversary of "25 years of quattro". The Audi plant in Ingolstadt focused entirely on this year’s motto in the course of these three days. As well as the development of various series-production quattro models, a range of race cars from the quattro era - among other things - were on display.