[cowmeat]

The wires are electrical taped to the stick shift shaft on my Insight and on both of my son's Insights, and there haven't had problems with any of the shift knobs. I'm pretty sure the shift knob on Turtle was the first one Daox ever made, and it's still functioning fine.
You do have to be careful when installing the shift knob so you don't pull any of the wires loose while turning it on the shaft (which is way easier to do with two people rather than by yourself), but once you tape them (or heatshrink them) onto the shaft there shouldn't be any of those issues.
A safer alternative when installing might be to just pull the shift knob apart (carefully accounting for each tiny piece), screw the lower piece on the shaft, then replace the buttons after feeding the wires down through when it's already in place, and then screw the top half back on.
I check mine regularly to make sure the ring of the collar isn't rubbing through the electrical tape, and since the threads on the shift knob on Ron Burgundy do allow it to move around a little, I plan on removing the top half and gluing the bottom half to the shaft.