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.
you are the only one that mentioned the correct socket size E12Hi,
I'm one of the happy ones who just installed the seat risers from SRAUTOSHOP. I initially had an issue with cross threading and was going to send the kit back but I talked to Chris who sells the kits and he thought it was an alignment problem. When you loosen the bolts the rail has a tendency to move a little bit. Just make sure to follow the instructions. I greased the threads with Lithium grease to make sure I wouldn't cross thread them. The front risers are 1" and the rear riser is 1 1/2". I payed $80 for the kit. Chris also works with a guy in LA, K5/Optima but it's Chris who sells the risers to him.
Chris is a very nice guy to work with. He's in Columbia, MO Good Luck
I used an E12 star socket to remove the factory bolts.
Chris supplies 4 hex head 2 70mm 10.9 tensile strength. 1.25 fine thread for the rear and
2 60mm 10.9 tensile strength. 1.25 fine thread for the front.
I'm happy with how this worked out. My spouse is 5'3" and we still needed a seat cushion. She now towers over me when I drive. Anyone over 5'3" should be ok without a seat cushion.