Thanks Evlengr. I found the attached diagram of the Kappas online. It looks like the total envelope is almost identical to the Rockfords so they should fit. I'm not a fan of ultra bright speakers.
As for future upgrades I was hoping to change out the speakers only but I'm willing to install an amp if necessary to get the sound I want. Do you know of any amps that would fit in the same space as the factory amp or would I have to mount it where yours is?
Another change I would like to make is replace the "sub" woofers in the floor but that can wait. I imagine that would need an amp upgrade so maybe I could do that at the same time as adding an amp for the mains if required.
2006 X3, Gray with Black leather, Premium, Sport, Cold, Xenon, Navigation, Privacy, Tow Hitch, Ipod & Bluetooth