[magnumfreak]

Here is a post from a very knowledgeable member over at lxforums:

"
vehicle mileage is stored by CCN (cabin compartment node/instrument cluster) and can only be overwritten by DCX approved service and repair depot. the PCM stores mileage as reference for emission controls and can be overwritten by starscan.
don't even think about installing a used CCN/cluster. vehicle configuration conflicts will affect most if not all vehicle accessories."