Raising the passenger seat a smidge.
 

Alright, I tried a quick and cheap experiment: I tried to raise the passenger seat 3/4 of an inch. In my head it looked nice with a bit more step up between the 2 seats.

Went to the hardware store, bought the necessary longer bolts and nylon spacers. Came home and started to work. Put the front 2 bolts on with spacers below nice and easy, felt good about what I saw. Came around back and was immediately stopped in my tracks.........

I had failed to take into account that the 3 bolts are all going in at an angle: forward leaning on the front, and rearward leaning on the back. TOTALLY MISALIGNED!

This is going to take some more fiddling around. Thinking through making some sort of custom mounting bracket.

Check out your local big box hardware store. They will have a good variety of brackets that you can possibly modify with little effort. Maybe just a little extra bending might do the deed. Wandering through the selection is a good way to develop an idea. As always, looking is free.