jpimpin: There's a ford part that hooks up to the antenna and lets you connect to the audio jack I've heard its a decent alternative but not great. As far as other options, I'm sure theres something that'll let you keep the oem HU but I personally haven't searched.
For those wondering about this piece, I have it and I love it. I have the audiophile and it works wonders. I dont have the armrest drilled, but am going a different route as far as making the cable look more OEM. to come at the end of the month....