On both of my Burgman 650 scooters the underside of the passenger handles had two threaded sockets on each handle, one toward the front and one toward the rear, to put in some studs to hook bungee cords to for strapping stuff on the back seat. Bungee hooks also could simply hook around the edge of those handles since they were somewhat hollow on the bottom with support ridges that also served to keep the hook from sliding up and down the handle.
The passenger handles on the AK 550 are a bit more solid and thicker so a bungee hook just won't hook around them. I was looking a little closer recently while trying to hook on my cargo net and found that the bungee cargo net hook would hold just fine at the very front end of the grab handle. I could wrap the middle hook around the handle and hook onto a cross strand of the cargo net. But the rear hook was a problem until as I was messing around the tip of that hook grabbed onto something just behind the rear mounting point of the grab handle. Turns out there is a hole back there on the bottom side of the grab handle. If that hole is threaded I could add a hook stud there using a stainless bolt of the right size and a brass bushing for a spacer and a stainless washer at the bottom end of the bushing to keep a bungee hook from sliding off. This would be the same setup I used on my Burgman scooters even though there is a kit for those. I figure I spent about 4 times less than buying the kit by buying some bolts, brass spacers, washers and making it all myself. Kind of my thing.
Found my inspection mirror so I went out to check out those holes on the bottom side of the passenger handles just behind the rear grab handle mount. They ARE threaded. Looks like M6 coarse thread bolt size. Maybe M8 but they looked a little smaller than that to me. In the next few months, need to work up the motivation to be in the unheated garage during the cooler weather, I'll remove the passenger handles and figure out what size bolt and length to get to put some bungee hook studs there.