Violation of warranty is specific to what you do to the vehicle. For instance a subwoofer install would not violate an engine defect neither would a suspension install. However the part you install and all components it effects it could void the warranty. I say could because it doesnt always but unfortunately it is on you to prove that it did not damage the vehicle if something happens. Kia has a lot of lawyers that will try to prove otherwise. Hope this helps.
Any type of modifications in your car would void the warranty and I don't think they'd like to deal with it but the final decision is yours!
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