My OEM radio went about 12 kinds of tits up and my really nice aftermarket Pioneer is too deep to fit in the Riviera, so for now my solution is a Lepai 2020A+ electrical-taped in place. Eventually I’ll replace it with a 7" tablet (probably one of those $50 Amazon Fire tablets) which will have an RCA cable running to my 4 channel amp and my 1-channel monoblock amp in the trunk, powering all of my speakers. I even found a way to power the door speakers with the 4-channel without running any new wires. Just connect the rear speaker connections to the front speaker connections at the wiring harness, then unplug the rear speakers and hook up the old rear speaker wires to the front speaker channel of my 4-channel amp. All I need now are the appropriate 3.5mm to RCA adaptors and three RCA splitters to take a single stereo channel and plug it into front/rear/bass.
This little amp actually sounds amazing. Can’t get too loud, but it’s fine for now.