RE: Charge while driving
Oh dear the hotrodder have moved over to sensible family electric saloon cars. Is there nothing they won't try to "improve"???
It's like this - you use a cup to move the tea to your lips, but not for getting water from the well. For that get a bucket.
For drinking tea, don't use a bucket.
Translating to cars. We have a brilliant set of in-county cars already in the Fluence and Zoe. Job done. No improvements needed, thank you.
We don't yet have electric cars for in-country travel save for the Tesla S, and it's over powerful, and too expensive. So we need to be patient, and wait for the new generation.
We don't have cross-continent (see how I carefully avoided saying in-continent) cars of any type, petrol, diesel or electric, although aircraft manage it, so it's not impossible. In fact most cars have enough range for one day of driving, 300 to 600 miles, no more. It's not an impossible target for electric cars to achieve.
Tesla have a big enough battery, but it's expensive, so have gone the route of putting in a big motor to classify the Model S as a performance car, which it is. But the cost is similar to a Maserati Ghibli V6 diesel which is better furnished, more beautiful, and cheaper to operate.
Converting a Fluence to run further would be better done by putting in bigger batteries, and then you would have to wire them in parallel, or simpler, have a change over switch between packs. There is insufficient space in the boot, so you will lose the back seat, plus a bit of acceleration.
There is a compromise to be made between power, weight, cost and a dozen other things. Most manufacturers are good at such product planning. A man working alone in his garden shed can improve some parts, but usually only by buggering up lots of other things.
Leave well alone when it works. And it works just fine right now.