I had the B&O on the Audi and that seemingly had no limit or clipping. At the high end of the volume (40+) it was just unbearably loud, without any appreciable distortion (to my ears anyway) so in practice it was more than loud enough.
On the Golf I've got the Dynaudio but I haven't really stretched it's legs all that much. It's got a lower spec on paper (8.1 speakers vs. 13.1 speakers and 500W vs 700W ish) but it certainly has enough punch for me so far. The system does sound a bit 'tinnier' than the B&O though and my (largely uneducated) guess is that the Audi was better sound proofed / damped inside while the Golf seems to have a few more exposed harder surfaces (e.g. plastic transmission tunnel vs. mono.pur covering on the Audi) which might be the problem.