If you are not using your windshield or top of dashboard, finding a spot is the most difficult task
If you can see from my very first top pictures of Arkon Mega-grip mount (btw, I went back to using it because it's grip fits every extended case), I'm using a dash mounted arm which attaches to vertical dashboard with 3M sticky tape. That particular product
SoundGate M2 was discontinued 3 years ago. I had to take out the mounting head and replaced it with universal ball joint head (dremeled out of another mount).
Regarding sticky mounting on vertical textured surface, it has to be a continues surface, not from different pieces, or at least a uniform area of the size of sticky gel pad. I don't have that anywhere on my dashboard where it's going to be mounted easily (for the reference, in pictures is GS350 dashboard). Also, out of 3 car mounts I tested (Arkon, Exogear, iOttie) I found only iOttie to have super strong sticky gel pad to hold to the vertical surface in the car where I had it mounted to the area above my glove box. The problem with iOttie, it doesn't offer universal ball joint connection so you can't mix'n'match mounts.
You know, in the worst case, you can get one of those adhesive metal disk for GSP mount (a few bucks on ebay) and sticky somewhere on the dashboard where you can attach suction cup of the mount?