can somebody pls help me on how to install an aux input in a 2007 audi a6.i dont have nav and there is no connector in my 6 disc cd changer in glove box..(including the radio wiring diagram)

 

You'll need AMI interface(MOST not the CAN) and the cable as well. Search on eBay, you could some AMI under $200, the cable for $20, $7 for the removal keys and the software upgrade disc(4610) for $10. The dealer will want $1200 for the unit and and another $600 for installation and also the software upgrade.
There is a seller from the UK that sells the AMI, cable, fiber optic cable(if you plan on keeping the CD changer), power supply cable(if you plan on keeping the CD changer) and removal keys for under $450 with shipping included(plug and play). All you need to do is buy the software upgrade disc if you need to.
Also you have other options Xcar interface, Gateway interface, etc., but you'll still need the software upgrade and you'll be trimming wire and rewiring.