trying to figure how to adjust the Apple CarPlay volume of Siri's voice. An example, when I ask Siri to send a text to somebody, whatever response she has is VERY loud! I figured there might be a way to adjust that, I just don't seem to be able to figure out how as I seem to have attempted various times with no luck. There's got to be something I'm missing somewhere, as there's several volume controls throughout the system and I may just not have found the one . . .

I noticed this recently as well. It was going on for a week or two and now things are back to normal. After things went back to normal I just assumed it was an Apple glitch that went away or was updated away.

While Siri is speaking just turn down the volume using the normal volume controls on the steering wheel or center console. Those controls adjust the volume of whatever is currently active.

that is what I do right away as its rather loud and it does lower the volume for the moment but next time the voice speaks, its back up to a loud level without me having made any other adjustments. That's the curious thing about this . . . I do not seem to be able to keep it set at a lower, manageable level. I thought there might be a 'central volume control' somewhere but if there is, which is doubtful, I do not know where its at. There's the knobs on the iphone, there's the volume control on the screen, there's the volume control on the steering wheel, there's the volume control on the center console and there's a couple ways to control volume within the MB menu's, which where I think I should be looking at but haven't found anything that is working as expected or hoped for . . .

I was thinking about this a little more, and remember it happened when I was on a road trip with Google Maps navigation active (w/muted instructions). Sure enough, I started a route on Google Maps yesterday on my way home and Siri was loud as hell while the navigation was active. Does that track with your use case?

Yes, I've experienced that, too in the past. It might be a bug in COMAND. I don't use CarPlay very often and I recently got an update for COMAND while my '19 C63S was getting its annual service, but haven't checked since then. I did use CarPlay last summer and over the holidays on trips to Europe, though, first in an Audi A6 and then in a Golf 8. Volume of Siri was fine there.

I don't think its in regards to any map use. I'm just driving around and remember I need to connect with so and so, I tell siri to send a message and response is loud. Or I get a message from somebody and want to listen to it, as soon as message starts playing volume needs to be adjusted quite significantly . . . when I use a map app, its usually Apple unless location I searched has a Google map attached and uses its directions. I have to pay a bit more attention or use Google on purpose like you did but I don't think it makes a difference . . .