2016 Chevy Cruze Limited Engine Whine

I just did an overhaul on my car audio which was disconnecting my rear door speakers. Installing new tweeters in the pillars and woofers in the front doors. I left the factory radio so I could retain my steering wheel controls. Installed a sub in the trunk and got 2 amps. One single channel to power the sub and a 4 channel to power the front stage.

I have an LC2i to get the signal from my factory radio. The main output runs to a miniDSP which then runs to my 4 ch amp and then front speakers. Bass output obviously runs to my mono amp then goes to sub. I finally tweaked everything and got the levels at a pretty solid spot that I'm currently happy with but I have a pesky noise that I can't figure out. When the car is in accessory mode I have a slight "static" noise that's sometimes more audible then others and at times it does this weird siren tempo like sound but it's very faint. Kind of sounds like a European ambulance but much higher pitch. When I start my car I have a fairly noticeable whine that increases as the rpms increase. I have a fuse distribution block which I ran 4 gauge Power straight from the battery to the trunk and then ran 4 gauge from the negative to the chassis of the car. Every component I added into my system all taps into the distribution block.

I even took apart my system again and ran a ground from the back of the radio to the distribution block per someone's advice and still no luck. I checked my grounds on my battery and didn't find anything loose. I haven't done the big 3 upgrade which was my last hope. I'm wondering if I should do the upgrade or just buy one of those devices I've been hearing about that is supposed to remove noise.

I don't have an aftermarket radio which I seen people trying to wrap wire around the RCA outputs but I tried doing it to my LC2i outputs just to see and that didn't work either. I've tried pretty much everything but upgrading the 3 wires to my battery ground, alternator, and engine ground. I looked today and they seem to be about 8 gauge from what I could tell. All solid connections. Not sure if bumping them up to 1/0 would change anything or not. I also didn't bump up the gauge of the ground wire on the back of the radio. The factory size is like 18-20 gauge so I just matched it and ran it to the fuse block. I seen someone post that you should splice in 8 gauge to the factory wire and ground it behind the radio.