I found that on the motorway the sound wasn't too loud, apart from when I accelerated of course. Certainly, at 70 odd mph I was able to have a conversation with Mrs Wigmog with the sidescreens on.
Whether I could put up with the noise on a very long trip remains to be seen.
Maybe if any on here who have had it done for a while could let us know if the noise or pops etc changes/lessens as time and miles progress, or do you simply not notice it after a while?