“Buy American” is a slogan that's getting a lot of attention lately, but it can be tough to put into practice when you're car shopping.

A U.S.-built 2017 Chevrolet Colo. with a diesel engine and a manual transmission might sound American through and through. But in that configuration, the Colorado is a worldly truck. The diesel engine is built in Thailand, and the transmission is made in Brazil.

American content in cars has been falling for several years, says Frank DuBois. DuBois is the creator of the Made in America Auto Index, which since 2013 has ranked automotive “American-ness” in a time of globalized car-making.

In 2013, the 30 most American vehicles in the index had an average of 77 percent “domestic” content (meaning from the U.S. and Canada; the U.S. labeling law doesn't consider Mexico a domestic source). By 2017, that figure had slipped to 72.5 percent.

Here's a list from car-buying website Edmunds: Vehicles that all are U.S.-built, with significant domestic content.

Half are from U.S.-based carmakers. The rest are from carmakers based in Japan that build cars in the U.S.

CONVERTIBLE & PERFORMANCE CAR

2017 Chevrolet Corvette

Made in America Auto Index rank: 3

Total domestic content: 82 percent

The 2017 Chevrolet Corvette is a unique slice of Americana that can compete on the world stage. This rank is for the Corvette with an automatic transmission. The manual transmissions for this car come from Mexico, and cars so equipped come in at 14 in the index.

COUPE

2017 Ford Mustang

Made in America Auto Index rank: 12

Total domestic content: 76 percent

The Mustang holds on to the American swagger that has defined it for 50 years. This rank is for the Mustang with an automatic transmission. The manual transmissions come from Mexico or China and cars with them rank 20 in the index.

CROSSOVER

2017 Honda Pilot

Made in America Auto Index rank: 9

Total domestic content: 78.5 percent

The Pilot has lots of space, a versatile interior and even a bit of off-road capability.

MINIVAN

2017 Honda Odyssey

Made in America Auto Index rank: 12

Total domestic content: 76 percent

Few minivans are better than the Odyssey when it comes to ample space for passengers and luggage and kid-friendly features.

SEDAN

2017 Toyota Camry

Made in America Auto Index rank: 9

Total domestic content: 78.5 percent

The Camry is a midsize sedan that offers a spacious interior and refined ride.

SUV

2017 Ford Expedition

Made in America Auto Index rank: 5

Total domestic content: 81 percent

The Expedition is one of our top recommendations for a full-size SUV, thanks to its massive interior, composed ride and towing capability.

TRUCK

2017 Ford F-150

Made in America Auto Index rank: 2

Total domestic content: 85 percent

Perennially the best-selling vehicle in the U.S., the F-150 has a diverse lineup of features, packages, engines and bed configurations.