Join Date: Nov 2018
Location: Seattle WA. No Niro yet but PHEV likely in my future
INTERIOR SOUND DEADENING: Based on personal experience and that of some friends, aftermarket sound deadening seems like a good idea, but it challenging to make a significant difference (ie greater than 25% noise reduction). Even with removal of entire interior (seats, carpets, door panels...) and $500 of materials you still are not gonna touch the noise coming from above the doors, front wheel wells, and engine compartment (minimal when in EV mode).
Doing so will improve overall quality of sound system but no dramatically reduce overall interior noise. IMO it is a lot of effort for a return that many people would scarcely notice unless they are true audiophiles (I'm not). That said, if anyone goes for this, would love to hear how they did it, cost, and degree of improvement.