My rule, when buying cars, is that each car should be more efficient than its predecessor - on the basis that fuel isn't getting any cheaper as time goes by.
I went from a Honda Jazz to a Toyota Prius. From there, I needed somewhere I could go that'd be more efficient, without being a massive downgrade in comfort and size. In the end I settled on a GM Voltec - mostly sold in the UK as the Vauxhall Ampera, with a small number of RHD Chevrolet Volts sold too (about 1100:100 ratio of total sales).
The Volt/pera is a plug-in car which also takes petrol. It's not a "plug-in hybrid" as most examples on the market exist - whether powered by the battery or the 1.4l petrol generator, it's always an all-electric drive (whereas plug-in hybrids split their horsepower 50/50 between petrol and electric motors, so are only all-electric at low speeds and low acceleration).
The idea with the Volt is that it eliminates the so-called "range anxiety" of conventional electric vehicles - the concern that you'll run out of battery power between charge stations - by allowing you to keep driving on regular ol' petrol when the battery is exhausted. The sacrifice in doing so is one of weight - it's a 2 tonne car - and battery capacity - I only manage up to about 40 miles all-electric per charge. It also sacrifices charging capability - the absolute maximum rate I can charge the Volt is 3.6kW (about 1.5 miles of range per 10 minutes charging). Which means charging during journeys is effectively useless - a 30 minute lunch break means only 5 miles of extra range, absolute maximum. For comparison, the common charge stations compatible with a full EV like a Nissan Leaf or Kia Soul EV can manage 50kW, adding about 80 miles of range in 20 minutes.
I'm sold on EVs as far as the drive goes. The Volt is the fastest car I've ever owned (8.9 0-60), it's astonishingly smooth, it's just so "normal" to drive.
What I'm not sold on is "range extenders" like the Volt. As a "my first EV", it's fine - but I find myself really wishing I'd bought a Leaf instead. With the charge infrastructure we have today in the UK and on the mainland, I just don't see the point. Almost every "long" drive I make I could make it there and home again on a single charge in a Leaf - but end up reverting to a tank filled with dead dinosaurs for the return journey when I'm in the Volt. And even then, I could charge up if I had rapid capability, but not with the slow-only Volt. It's 36 miles to the nearest IKEA - I could get there & back easily in a Leaf. But I wouldn't need to - they have rapid EV charging spaces right next to the entrance. If I drive north on the M40 I could charge at every other services (e.g. I'm at J11, I could rapid charge at J10 or J12.5). If those stations had Volt-compatible charging, it'd be pointless due to the slow speed (although J8A *does* have Volt-compatible charging, and like I said, it's basically pointless).
Not to mention the cost. I did the sums - driving to the in laws' holiday home in South France is about 500 miles each way from here. I could stop every couple of hundred miles and fill the tank with dinosaurs - or I could get free charging at every major supermarket in France (and the major motorway services between here and Dover). I'd stop a bit more for a piss/coffee break than driving a normal car (or the Volt after the first 35 miles) - how utterly terrible.
I don't see myself buying a dinosaur-eating car again. What's the point? There'll be a price crash on current ~100 mile EVs like the Leaf or i3 when affordable 200-milers like the Tesla Model 3 land in 2017ish. But even those 100-mile EVs just make way more sense to me than what I bought - I just don't know if I'd have been in a position to reach that realisation if I hadn't bought a half measure first.
The Volt has plenty of positive sides. The big downside is it's exactly what I wanted - and what I wanted was wrong.