Just thought I'd let everyone know: I replaced the stock non-HK rear speakers in my late-2006 MC last evening, and was surprised to note that the stock rear 6x9s were not those odd 5-ohm ones pulled from earlier MINIs. I had good-ol' 4-ohm versions in my MC (made by Philips, according to the sticker on the magnet).

An installation note: the Infinity Reference 9612i does not simply drop in to the cutouts in the rear. Its basket bows out a little too much for it to fit cleanly ... and the stock hex-headed sheet metal screws won't work with 'em, either; you can't get a socket head or a wrench onto them. I had to fish for equivalent Phillips-head screws in my box o' random fasteners and pilfer a few more from my component kit for the doors (Infinity Reference 5012cs) to install the 9612is. Seems to be working fine, though ... and the difference in sound is dramatic.