Hi,I had two minor gripes about the Kona, the low passenger seat and the lack of AC vents in the rear.
I ordered 4 custom-made seat frame adapters from a machine shop. They are 3 inch high, 3 inch long and 2 inch wide. If they are wider than 2 inch they won't fit.
In the center there is a hole, 11 mm diameter to accommodate the original bolts, which are 10 mm.
The two rear adapters need a cutout, only on the top, to accommodate a dowel pin in the two rear seat anchors. After drilling the larger holes I still had to cut out some more with a grinder. This cutout needs to be 19 mm or 3/4 inch wide. The fronts only need one hole in the center. Check the photos.
The original bolts hold the adapter to the floor, the bolt size is 10 mm x 30 mm with a 1.25 mm pitch. You need a 9 mm or 3/8 socket, a 12-point socket to remove and re install the originals.
I purchased four extra bolts and nuts and some washers from Ace hardware. These hold the seat frame to the adapters.
Once you have everything the labor is less than an hour and it can be easily reversed if you ever sell the Kona. Liability?
The passenger seat now is a bit higher than the driver seat when that one is fully raised. I am 5'9" and I can be comfortable in the passenger side. My view out is better.
As a bonus you get a 3-inch space under the passenger seat for a laptop and two large cameras.
During the installation don't tighten anything until all bolts are in place, then tighten the four original bolts going to the car's floor before going to the others.
By the way, there is an AC vent for the rear, under the seats and non-adjustable. Check the photo.
My cost, machine shop and the extra bolts came to $ 38.
If you want a 2 inch lift only, the 9 mm socket/ratchet won't fit. You could tighten the original bolts with a wrench, but a 9 mm wrench ( too short) isn't strong enough for the torque required.