Seems very integrated into the vehicle. Who is selling aftermarket versions?

I'd swear I've seen such systems advertised in the appropriate magazines for large RVs (Class A "tourbus" RVs), but for the life of me a web search brings up nothing. For now, assume I hallucinated such a thing (or maybe what I think I saw was actually just an old-school steering stabilizer that advertised "crosswinds!".)

And you're right, it does seem that the systems are integrated. For example, Mercedes' system for the Sprinter applies the brakes on one side to compensate. Seems like something would need to tie into the CAN bus to pull that off. Not that aftermarket couldn't do the same, but is that functionality even available on a 43' pusher diesel?