RoverOne Car Multimedia Player for Mercedes-Benz C-Class W203 C200 C180 CLK W209 Class 2004-2009 with CarPlay Android Stereo GPS Navigation Radio Bluetooth

I bought this for a 2006 C-Class 350 (W203) after the seller told me it would work just fine in it. After waiting for the shipping and getting it installed by a professional, the radio has some weird crackling audio issues. You basically cannot hear bluetooth calls, or reproduce music or videos or anything because the audio sounds terrible after a few minutes (works fine at first). For some reason the AM/FM radio and CD playback work fine (it is not an installation issue, otherwise thing would not work at all).The seller had me update the firmware, but the issue persists. They also don't seem willing to take it back for a return and have suggested me that I take it to a "professional" to get it fixed and they would cover it (???). The worse thing is that between how long it took to get it shipped, plus getting an appointment to get it installed and the back and forth debugging emails with the seller, the Amazon A-to-Z guarantee has expired and now I am stuck with a radio that doesn't reproduce audio properly and a seller that won't take a return. $500 down the drain...Do yourself a favor and buy a different radio, from a different seller.