So a prius is 110% self contained.
YES.
There is the new Prius "plug in hybrid", which is similar to the Volt though. You dont HAVE to plug it in...it has a gas engine...and can operate self contained. But if you want to use less gas, you can plug it in, and it will go 70 miles or so on pure electric, before the gas engine kicks in. Like I said though, YOU DONT HAVE TO PLUG IT IN. ITS NOT AN ELECTRIC CAR.
That new version of the Prius, is only an option. When you buy a new prius, you can get the regular one (that you cant plug in), or the "plug in hybrid"...which is not an electric car. Its a plug-in-hybrid.
Like I said before, 99% of the Prius's you see driving down the road are normal hybrids. No electric plug, etc. There are no prius's that have to be plugged in...they are all self sustaining (thats the word you were looking for, not 'self-contained')
The only three vehicles in the US that HAVE to be plugged in, are the Tesla, the Nissan Leaf, and golf carts.
Why is this so hard to understand?
Ben