Regrading the Prius-- This is possible.
However, there are some issues to keep in mind.
1) your draw is going to be limited. In my last car, the fuse on the lighter plug was a 10 amp--- which means 10 amp * 12 volts- 120 watts. Surge over 120 watts can blow out that fuse, breaking your system. This will not happen charging a phone, but do not plug in anything big.

2) Are you willing to leave your car ""running"" with the keys in the ignition? The ignition must be in the on position for this to work, otherwise you are just killing the starter battery. Maybe keep it in the garage, but run a pipe to outside for exhaust like a Car Shop? Sit in car while charging? Not nice to have a generator that can literally drive away.....


Regarding Generator vs Solar. I kinda think this is size dependent, and time-frame dependent.

Small and long term Solar wins hands down. I have a 21 watt Aukey I bought on Amazon (now 45.00, I got for 34 on sale). It will charge 2 devices at 2 amps each; no gas, no noise, good for a decade. It is only USB, so will not charge 12 voice stuff, but for small/camping, do not care. Not perfect, I have 2 or 3 of those 10$ 4000Mah battery thingies for rainy days.

Big and short= generator. I have a 1200 watt Menard's Special; will run my fridge and freezer, will run 5 hours on tank, have a 5 gallon can that I dual use for lawnmower and generator to keep fresh.


Big and LONG?.... ick.
I have several larger Solar panels and batteries that I have play--- unm... I mean EXPERIMENTED with. Hypothetically, I could run either my fridge or my freezer (not both) indefinitely, or at least until the gold cart batteries die of old age. I did the freezer for 24 hours as a test, no issues.

frankly, the parts for the solar cost more than just buying gas would have cost (assuming I can get gas) between the panels, charge stuff and batteries, though WAY cheaper than 10 years ago.

Frankly, a 50 watt panel, a 15$ controller, and a golf cart battery could charge all the small stuff in a house for less than 200$ phones, tablets, laptops, smaller AA,AAA,D....