Volkswagen's global-scale diesel-emissions scandal has sucker-punched diesel engines something fierce.

That's exactly why if I were in the market for a new or used vehicle in the next few months, I'd buy something – anything – with a diesel engine.

First because diesels, scandal or not, are the car industry's best-kept secret. And now, VW's nefarious dealing virtually assures that those who aren't scared off can drive a fantastic deal on a diesel-powered vehicle.

And not just for VW models.

Think of it like the stock market, where the time-honored adage is to buy low and sell high. Right now, diesel definitely is "low," and if you're a car shopper with checkbook in hand, the next few months might represent an unprecedented opportunity to get a bargain price on a fuel-saving technology that's had its reputation dinged not for any rational reason, just corporate hubris.