Try cleaning the inside of your rims first. I had a 2002 LX and everytime I used to get the same thing I just cleaned out the dirt and it drove just fine. I had it for 3+years and 73000 KMs on the factory balancing.
For some reason these rims collect a very high amount of dirt. I even had my tires rotated once and the shaking went from the front to the back.
Hi!!! New to the list, just read about the wobbling you have. Just had the same problem, found out from my dealer service manager that the tires Kia uses are crappy and need to be rotated and balance religiously every 5000-10,000 miles. This cleared up my problem right away. Good luck