Our customer was handed down this 2005 Toyota Prius from her parents and wanted to upgrade and fix some of the tech issues with it. One of the door speakers were blown and by modern standards, the car was feeling quite dated. She wanted a setup with Apple CarPlay so we recommended the Sony XAV-AX1000 which is one of the most affordable CarPlay head units. The convenience of the volume knob makes it so that many customers can skip retaining steering controls which saves a fair bit of money.
The factory JBL sound system is not bad but she had cranked it too loud and blown one side of the front speakers so they needed to be replaced. We upgraded it to JBL's top of the line Stadium GTO 6.5" coaxials which can handle just about all the power this car can throw at it. To address the bass issues, we also installed a Pioneer TS-WX1210A powered subwoofer in the trunk. This subwoofer has a gain control knob which we installed in the center console just below the new head unit. One additional concern our customer had was that the car was quite loud so we added some sound deadening to the front doors to help since we had the door cards off anyway. This also improves the overall sound quality with the new system.
We also did an 18% window tint on the rear windows which keeps the new subwoofer out of plain sight.