Hi all. Just picked up a 2012 Sport, and made the (incorrect) assumption that the "Sirius" button on the head unit meant that it already had a sat radio receiver installed. Once I figured out just how wrong I was I asked the dealership service guys how much it'd cost to add the receiver. Their quote of around $540 installed does not appeal to me, to put it mildly. So now I'm wondering if any other Mazda OEM units (3 or CX-9 maybe) are direct drop in replacements? I've seen some pulls on eBay for relatively cheap. Any advice is appreciated! Thanks.