thanks for the info if you got it.

 

dash control interface

allows you to retain control the dash controls of the head unit when you buy an aftermarket head unit.

 

If you are not installing an aftermarket headunit, I wouldn't worry about it, but if you do, it is almost a must have. When you install an aftermarket headunit, you lose the controls on the left of your steering wheel that normally controls the radio. The DCI is a mod/chip that gives you that control back once the aftermarket headunit goes in. It also gives you some additional functions like speed sensitive volume etc.