I will be replacing the Canton system later on with new amp and dsp. But for now I've upgraded the center speaker already with a Hertz ML700.3. I've made a speaker adapter that will fit perfectly. Speaker is also a 4 Ohm speaker. Sound quality is amazing. I will upgrade the tweeters in front doors soon. As they are also 4 Ohm.

interested to hear what you're replacing it with. looks like I will be driving a Kodiaq soon not a Superb, and I have a decent system for that, but not 3-way, not with a centre, and with a big ol' 10" sub. @KoenG