I am sure this is a redundant question, but I am a new X5 owner(2001 Oxford Green 4.4i) which i love, but it has the smaller screen nav setup. Am I able to upgrade to the wider screen DVD-based nav? Where would I buy parts, and I am definitely not going to install it myslef, so would afternarket people do it and it work authentically? Live in the DC area. Thanks for any replies to this.