HU-850 Replacement: Amplified Antenna?

[bnilsson]

I replaced the failing HU-850 in my 2005 S60R with an aftermarket Pioneer unit and a faceplate adapter kit that all went in nicely, and I was able to preserve steering-wheel controls with an Axxess kit. But my radio reception is worse (especially AM). I've seen some messages that suggest there's an amplified antenna that needs a power lead. The antenna adapter I used (like this one: http://www.scosche.com/99-01-ant-adpt-volvo-s80) contains no power lead, and I'm wondering if I should be using something like the Metra 40-EU56 (shown here: http://www.metraonline.com/part/40-EU56), but with a Volvo-specific interface. I can't find such a thing, so I'm hoping you can help. Thanks!