I have a GLA 250 (2017) with about $40k miles. I am the second owner. Vehicle is certified until Nov 2021. Amp started making loud crackling and static noises a few months ago. Took to MB dealer to diagnose. They said amp had water stains and had gotten wet. Warranty will not cover. I'm shopping OEM parts for a used one since MB was going to charge $1500. My questions...does anyone have any experience replacing just the factory amp? Is it a simple plug and play or require factory programming, rewiring, etc.? Any suggestions where to get the part and knowledge about installation would be greatly appreciated!