Hello. I have a Panasonic CQ-VD6503U installed on my 2000 s-type and lately when I accelerate, the sound goes out on the inside speakers. It does that more often when i am above 30 mph. I also have a subwoofer in the trunk and that seems to work fine, the sound doesn't cut on the subwoofer only the inside speakers. I went to the guy who did my wiring and he told me there is smth wrong with the head unit itself, which I highly doubt it. I forgot to mention that my alternator fried a week after this problem started. Any thoughts? Thanks in advance.