Possible blow out with fuse A?

[SeaSteve]

Here's a question for the electronics guys: why don't vehicle radios and clocks use non-volatile memory (like in flash drives) so the presets and clock time don't get lost when the battery is disconnected?

It has to come down to cost. Why install non-volatile memory or a "watch" battery when you already have a constant 12VDC source. Yes, you would keep everything "stored" when one removes the leads to the battery but that SHOULD happen on very FEW occasions. Also it would take a LOT more to power a crystal oscillator and keep a timer/clock going than a standard USB has to simply refresh it's "stored" ones and zeros data.

It does make sense for the radio and other settings but adds more cost to an industry that has done it the other way for many years.