Mostly the differences I found for suspension was the rear, the rear lower arms are aluminum on the cadenza and the rear spring and rear sway bushings and the bar itself are different part numbers but after close inspection between the two cars and using dial calipers they appear to be identical. So i will let you guys know if it fits especially since i will be ordering it from k5superstore as I do with all my parts, well minus the coil overs.
I had optima k sport coil overs for the 2013 up maybe that is why they worked the only modification I had to make was to the abs/brake line bracket. I didn't like the one included in the ksport kit so I made one that looks much nicer. I had no problems with the install besides how long it took to figure out the ride height i wanted. Alignment is within spec and so is the Camber.
Oh and I use kiapartsdepartment.com to reference part numbers.
Next i am going to see if I can fit the oem optima ram air on the cadenza, the took looked identical I just haven't had time to try it between the two. I want the optima one as it eliminates the air resonator found on the cadenza one.
Here is the cadenza and below is the optima, I am talking about part 12 and 18.