what is the best wired fm modulator?

I'm getting a Saturn Astra, and it doesn't have an aux input. I don't want to replace the head unit, for several reasons (it controls the on-board computers, I like the factory look, and don't want to spend the money). So I'm left with FM modulation to get my XM installed... What is the best wired modulator? So far I've only found this one: http://www.crutchfield.com/App/Product/Item/Main.aspx?g=234550&i=142FMMOD01&tp=1287 and this one: http://www.crutchfield.com/App/Product/Item/Main.aspx?g=251550&i=040SA10112&tp=1701 I think the Delphi one might work better, and it was developed specifically for its XM receivers. What do you guys think? Is there another brand out there that I should consider? What are your experiences? I just want what will sound best. Thanks

Your second link (the delphi model) will definitely be your best bet. It passes the signal through the antenna wire so you wont need an extra wire coming out of the xm radio. The second advantage is that it is auto sensing so you wont need to mount a switch. The modulator automatically turns on and off with your XM radio.