Do you mean a roof carrier?
http://www.roofbox.co.uk/scripts/rb..._long_no_tu859/Qx@w,6M42VAwp3@Rb{~cC4urewJaWo
You'll need bars to attach it to:
http://www.roofbox.co.uk/scripts/rbvehsel3.php?query=7970&emulate=roofbar&vptype=500861
I use Thule Wingbars on my Panda 4x4, very quiet, though prone to bumping my head on the ends when installing the kids car seats in the back. Wingbar Edge are apparently too narrow to safely fit all but the narrowest of roof boxes to, so options were limited. Speak to the people at Roofbox.co.uk - they're really helpful and price competitively (I've always had excellent service from them).
Re: Blue & Me, My iPhone5, once paired, connects seamlessly to the Bluetooth and can both make/receive calls wirelessly and stream music either wirelessly or with a USB lead connected. Charges perfectly etc (but does need to be a 'ready for iPhone' approved lead). For music playing, it's better to have the lead connected as you can browse your music catalogue via the steering wheel controls, whereas your passenger has to do this if wireless (though +\- track and volume commands work on the wheel in this instance). I guess it will depend on your phone and operating system?