Since this thread’s been revived and so many people run into this problem, thought I’d add my $.02.
I don’t have a poptop (yet) but my rig is tall, I’m 5’ 6”, and not very strong. Had to figure a way to get my kayaks and canoes up there without any help. So I installed four 66” Yakima bars and put one as far back as I could get it. You use that rear bar to roll it on (No need for those fancy rollers... the bars are slick). I stand the kayak on its tail end on a blanket and rest the bow on the back bar. Pick up the back end and roll. It doesn’t take much to get it to tip and bam, down onto the bars or kayak saddles. The taller you are, the easier this will go. I use a camping step stool for the first step, then a hitch step, and finally, the van opening. I use one of those “grabbers” to pull my straps over the top using the stool or barn door/passenger door steps. Getting it down is a piece of cake, more gravity on your side.
I like the looks of those Yakima Showboaters, but you still have to be able to reach, and now you don’t have gravity on your side. I’ve been carrying kayaks around for 40 years and tried every darn way till I finally settled on this one. It’s cheap and easy. And if you need more height, get yourself a skinny step stool to hide inside some nook or cranny.