In the old days, a “dirty” (cheap?) analog amplifier would have the floor noise be quite audible if you crank up the volume, because the signal to noise ratio of the amplifier is poor. Nowadays with digital amplifiers, the SNR is good enough that you’d be hardly pressed to hear any floor noise.
To my surprise, when I first got the OPN 1, although I didn’t notice any floor noise, whenever I put it in full directional mode, if I’m in a quiet environment, I would notice the floor noise if things are quiet enough around me. I started reading up and sure enough, there has been research papers mentioning this effect in directional modes via microphones control. Generally, in this mode, it would cause a low frequency roll-off, and as a result, the system compensates through amplification at the low ends, resulting in higher internal mic static noise level (what I call floor noise). I learned about this when I was trialing the Sonic Enchant 100, where they tried to solve this issue by creating a multi-frequency band design so they can leave the lower frequency bands in omnidirectional (to prevent the low frequency roll-off issue) and only activating directionality in higher frequencies. But apparently the OPN doesn’t have this multiband design feature because I can hear the floor noise in full directional mode.
Anyway, to make the long story short, it sounds like what @Kem103 is hearing in the car or van may be this floor noise, especially confirmed if it’s diminished when the volume is turned down. Perhaps the More somehow switches to Full Directional mode for some reason in the car and van, maybe because the conversational speech wasn’t clear enough, and this resulted in the low frequency rolloff amplification to compensate, making the floor noise heard more clearly.
Of course this is all a guess. But if it’s not the road noise or the wind noise and it sounds like the constant floor noise of the amplifier, then this is the only plausible thing that comes to my mind.
If playing with the MoreSound Intelligence parameters in the screenshot below doesn’t seem to help, you can try to have the audi create an custom program for when driving and set the Directionality Settings to Fixed Omni (as seen in the lower right hand corner of the screenshot below). This will force the More to not be put in the Full Directional mode, thereby avoid the low frequency roll-off situation and help minimize the floor noise you hear. However, this may force you to hear the road noise more, so you may end up avoiding one thing just to hear a different thing anyway. But it’s worth trying out, so that if it helps, whenever you’re driving, you can go to this program which is optimized for driving, then return to the default when you’re not driving anymore.