While falling gas prices are good news to most of us, for the makers of one of the most fuel efficient cars on the market, the Toyota Prius, the news is not so good; as sales of the Prius have been in a decline since 2012.

And just when things were starting to look a little better with the recent launch of the 4th generation Prius, we get word that it’s highly anticipated plug-in variant that was set to go on sale this fall, will be delayed a few months, possibly into next year.

The PHEV Prius Prime, features a larger battery to extend full EV driving up to 22-miles, and is expected to earn a 120 MPGe rating.

Thanks to the Chevy Volt and others, plug-in hybrids are no longer a rarity. So the Prius Prime will still face stiff competition when it finally arrives.

We’ve all seen them on the road; those not quite cars/not quite motorcycles 3-wheelers, with 2-wheels in the front and one in the back.

Well up to this point, regulations for these go-kart-like machines have been inconsistent at best; with most states classifying them as motorcycles. That means you have to get a motorcycle license and in many states, wear a motorcycle helmet as well.

Now regulations are slowly changing, as states have begun to classify them as Autocycles. And provided it has a proper steering wheel and a roof, helmets aren’t required.

Autocycle offerings range from the performance-minded Campagna T-Rex and Polaris Slingshot, to the more eco-minded fully electric 3-wheelers of Elio and Electra Meccanica.

While makers of 3-wheelers have been trying to get rid of motorcycle classifications for years, they should be careful what they wish for, as motorcycles do not require crash testing. Likely relaxed regulations in one area will require more scrutiny in others.

From plug-ins to Autocycles, you never know what changes consumers will face in an ever changing automotive industry. And that’s it for this week’s Motor News.