A note on the ipod upgrade - if you have a 5th gen ipod, you might consider skipping the extra expense. The xA still has the auxiliary jack and there is a great product from Ten Technology:
(http://www.tentechnology.com/products/products_flexibledock.php)
that allows you to see the screen and run a line-level output with a 1/8" jack. The lighter is a bit low for it to be perfect, but if you have a video iPod you might rather have the attractive iPod screen to look at rather than the installed deck - which didn't impress me on the test drive.