i'm pretty sure anything that may slightly even effect the performance of any given system it will void the warranty i.e. i/h/e would void out the engine and possibly the drivetrain(they didn't "intend" for it to handle that much power when they warrantied it) and i can understand about the aftermarket alarm cuz it affects the electrical system(once again they didn't "intend" on it having to handle the extra load + what if you wiring it wrong and mess something else up)

and in response to hyundai's in general, you get what you pay for, a brand new car(which is gonna need that 10 yr drivetrain warranty so i suggest you don't void it out)