Detroit had a good year in 2014, selling 16.5 million autos — up 1 million from 2013. The stock of Ford and GM has revved on the good news, jumping 5.7 and 7.8 percent, respectively, in 2015.

That’s better than the S&P 500, which has risen 2.5 percent.

Motorists responded well, not only to low-interest-rate loans but to all the technology in cars today — everything from touch screens and Wi-Fi hotspots to hybrid technology and back-up cameras.

But in just one week, Detroit’s vibe has gone from hip to has-been.

With reports last week that Apple hopes to bring a car to market in five years, every motorist who remembers the pre-iPhone era of smartphones must be feeling like their new car will go the way of BlackBerry, Nokia and Palm Pilot.

Currently, at a secret location near its Cupertino, Calif., headquarters, Apple is said to be working on a car design — code-named “Project Titan” — at breakneck speed. While auto companies can take as long as seven years to develop a car, Apple is said to be hoping to start shipping its vehicles in five years — as early as 2020.

Elon Musk’s Tesla is currently the No. 1 electric car maker — with vehicles ranging from $70,000 to $100,000 — and Google is working on George Jetson-like driverless cars. But neither is close to cornering the market on mass-affordable electric cars.

My sense is this is where Apple will attack — just as it had with smartphones, laptops and tablets.

Former Ford engineer Steve Zadesky is heading up Titan.

Efforts to fast-track the car project got Apple in a little jam last week when a car-battery maker, A123 Systems, sued it over alleged poaching of its executives.

How badly does Apple CEO Tim Cook want to get this car out of the garage?

Well, Apple has been offering the best and the brightest in the car-battery field $250,000 signing bonuses plus salaries 60 percent higher than what they currently earn, Musk told Bloomberg Businessweek this month.

Take Marc Newson, who just so happens to be close friends with Apple’s design guru, Jony Ive. Newson, hired last September by Apple, is considered one of the more elegant engineers in the world.

The guy has works archived by MoMA — not something you hear about a lot in Detroit.

Zadesky, the boss, besides holding 90-some patents, was the sole signatory on a 2010 business contract with an organization called Liquidmetal. It is known for Moldable Metal — “Nanophosphate metal” — which can be shaped like plastic.

Detroit still welds.

Apple and Liquidmetal have filed 17 patents together — 14 in the past year or so.

It’s this kind of think-way-outside-the-box process that elevates Apple above its peers.

When Carl Icahn said earlier this month that he thought Apple shares — which closed Friday at $129.49 — should be valued at $216, giving it an unheard-of market cap of $1.2 trillion, lots of people laughed.

After researching Apple’s plans for the car, heck, I think Icahn may have been aiming too low.

Get ready, America. The new Motor City is not Detroit. It’s going to be Cupertino.