Is it possible to upgrade the stereo on my recently purchased 2018 Ex-L to the 330 Watt with the subwoofer? Failing that would it be possible to upgrade the stereo at a shop without compromising the electrical/warranty?

 

welcome to the forum. glad you asked before doing any mods. you need to always ask the honda dealer service dept, before you do your mod, some will tell you to buy the upgraded stereo and have them put it in, this car still being under warranty, if any electrical or stereo components fry, they will warranty the installation. if you are anyone puts it in and it frys, you eat the repair and possible to loose all the warranty.

 

Is it possible to upgrade the stereo through Honda?

 

you might call the service dept and ask what they can or cannot do.