I am swapping someone thier 2001 tails for my 2003 tails. Now I read where you need to get the adapter for the 03's to work in the 2001 car. But as far as my 2003 using 2001 tails, will I need an adapter??

What is the adapter for?

 

just look what was the extra pieice u have it should have the braket the just give it to him if the 01's dont use it.. just an idea