I've seen many discussions about this issue in many forums, yet it never gets fixed. Let's try to state the problem clearly. Spotify, you stutter when playing via bluetooth on Andorid. The sound just drops out anytime something like a notification, etc. occurs. Despite me having most of them turned off. Despite me turning down notifications and system sounds to zero, you still stutter. So when driving, rocking along to some great music, it just drops out. It happens whether I stream or have saved the music on my device. It is so super annoying that it vastly reduces the time I use Spotify in my car. It's sad that this hasn't been fixed.
Is this a Spotify only problem? Kind of, but mostly, it's an Android problem. It handles notifications poorly. Regardless, apps like PowerAmp have a setting to try to take over the notifications and block them. Seems to work much better (but not 100%) than Spotify. So that tells me that it is possible to write software to block notifications; yet Spotify just won't do it.
So here's my ask. Spotify, please add a setting to your Android app called "I want Spotify to rule all my notifications and system issues by taking all priority on my phone. Other than phone calls, block any form of issue that would cause stuttering by managing cache better and blocking the interruptions." Put a second setting that says "Include calls in the above blocking". And do a little programming.
I don't think much is required. You could for example, redirect the notifications in some way. You could raise the priority of Spotify in the operating system. You could cache more of the song and then as annoying system notifications come in, strip them from the cache and replace the missing music there (or re-cache). You could create some kind of virtualized container that runs on top of Android, but that is self-contained and we could just run that (OK, farfetched, but you could). My point is that you have to fix this if you want people to use Spotify on Android with Bluetooth. Seriously. Work with Google. Hack the operating system. Publish your own ROM/Kernel version and we'll all unlock our phones and use it. Just fix it. Please.