Lunchbox, I think you've gotten all the "help" you're likely to get here. The trouble is your requirement that the method be low profile and unobtrusive . . . rifles just aren't very small, and motorcycles aren't very big. You might look into something that goes smaller than a folding AK, such as one of the SU-series rifles from Kel-Tec.
I have to say, though, I don't quite get what the big drama is. Is everyone here really saying that a guy on a motorcycle can't carry a rifle around? I mean, it wouldn't be my choice, but I don't have an AK in my trunk, either, or a rifle rack in my pickup. A lot of people do carry rifles in their trunks or in the backs of truck cabs, and I don't hear them getting this kind of grief. Would you all have treated this guy to the same snark if he'd asked "Which is a better truck gun, AK or AR?" Somehow, I don't think that would have started three pages of "Just what do you think you need a handgun and a rifle in your truck for, you 12-year-old poseur?"
I don't work in Florida, but I'm pretty sure no one at my company would declare a scene unsafe because there was a rifle in a vehicle, encased on a vehicle, or on the ground. An AK with a runaway trigger? Seriously? He shouldn't carry an AK on a motorcycle because if he's in an accident, and the rifle is ejected from its case and lands on the ground, emergency personnel arriving on scene will be in danger of that rifle going off and going full-auto as it lays on the ground?
This isn't as hard as some of you are trying to make it. He needs to carry the rifle safely and discreetly if he's going to carry it on the bike at all. If you know a way to do that, you can help. If you don't know a way to do that, you can't help. Easy.