My opinion:
* 8-speaker, 12-speaker, ..., ∞-speaker systems are a marketing gimmick.
* door-mounted speakers are a path for road noise and it's better to put speakers in sealed pods.
* a quality, separate, aftermarket amplifier is better than any head unit's built-in amp, but a modern, quality head unit's built-in amp is better than what these Toyotas originally came with (especially when you consider degrading, old electronics).
* "smart" head units are a waste of money. You're already upgrading your smartphone regularly, so let the stereo be a stereo.
I say just bypass the stock stuff, wire a quality head unit to quality speakers (however you want to mount them), and properly adjust your EQ. PartsExpress.com carries this inexpensive, calibrated microphone. Using an iPhone or Android audio analysis app and sound test files allows you to dial-in your EQ and compensate for variances in components and vehicle interior.
Dayton Audio iMM-6 Calibrated Measurement Microphone for Tablets iPhone iPad and Android The Dayton Audio iMM-6 is a professional-quality measurement and recording microphone that is designed to work with the entire suite of Apple "iDevices" – iPad, iPhone, and iPod (with 3.5 mm jack). The...
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