Bought my car new 6 moths ago, after braking hard at speed one day, the car then began to vibrate when ever braking over 60MPH and it then gradually got worse, so they replaced first the front at 3K then the rear rotors at 3.5K. At 6.5K miles, they have now gone again. This is clearly a manufacturing design fault, they are simply not fit for purpose. I'm in the UK so all the stuff about "they are better pads/rotors" in Europe is none sense. I have ordered in a set of performance rotors now from the states and had them shipped in for the dealer fit, but this is at my cost which I do not feel is fair at all. Also the people who claim its pad deposits - clearly they have not experienced the warped issue. Basically if you brake hard at very high speed, thats it, they warp! I am surprised you guys in the USA have let them get away with it, I though you were all hot on legal stuff there and would have had them before a court long ago when their never ending redress is simply (some time reluctantly), replace them with the same "un-fit for purpose" for it to sit there waiting for this to happen again as soon as you want to brake hard at high speed again. Its a very sad situation and has taken some of the shine off it all for me, not sure I would want another Kia in the future.
This is exactly what happened to me.
Bought my car new. After almost 6 months (about a week short of six months) and at barely a dozen miles above 3000 on the odometer the problems started. It took them another 6 months over the course of another 3000 miles and 5 trips to the dealership to finally fix the problem.
What worries me is that you say you're in the UK and they replaced it with UK parts and the problem continues. I guess that will happen to me as well. I think there is a possibility that some Stingers are just garbage from the factory and when people replace with the Euro-spec parts they might still continue to have problems... It's only been about two months and 400 miles since my problems have been completely fixed... I hope they do not return...
Also, with the legal thing, I did get an attorney and I have been compensated for my time lost from this. I'll leave it at that. Plus I still have the car under warranty. If the problem returns again I can have it fixed.
I will tell you, when we were experiencing the problems, it was terrifying at highway speeds. The entire car would shake so violently and the sound was crazy loud. My gf and I both have multiple recordings of it. Even the people at the dealership who watched the video said that was the worst they ever heard/saw it. When I took them on a test drive and showed them they were in disbelief how bad it was. The problem was pretty noticeable even at 20mph which was ridiculous.
I don't blame you not wanting to get another Kia in the future. This was my first one, probably gonna be my last one, but I do like the car a lot. If it wasn't for the garbage brake system and the terrible dealership service/experience I would love my experience much more.
I do find it tiring when others are saying that the problem is with the driver and not the car itself. I drive very calmly and slowly and it happened to me far too many times. It's easy to say the issue is driver related when the problem hasn't happened to the person because they got lucky.
I remember all of my friends with WRX's were spinning rod-bearings and their engines were exploding on each other. Ironically, all of my friends had heavily modified WRX's. Everyone was telling me how smart I was keeping my car stock and that it would never explode. Ironically after the 2nd year of ownership the same thing happened to me on a stock car... certain companies take shortcuts when building nice cars and it shows... I'll leave it at that...