I purchased this 200W luftmusic bluetooth amplifier for installation in my '72 BMW 2002tii. Bench testing the amp shows promise. It has USB input and USB charging, Aux input and bluetooth. Remote is completely wireless and charges via USB type C.

Wire the red wire to a switch power source since the amp does have a slight power draw when turned off.

Link to Amp
https://amzn.to/3bRhgpX

You might be able to find it cheaper on Aliexpress.