Depreciation is a huge cost when it comes to owning a car. But did you know cars depreciate at vastly different rates? According to a new study from CarGurus, changes in vehicles' values (model years 2008-2012) varied from -18.9 percent to +3.4 percent.

“All cars lose value over time, and it seems luxury vehicles do so fastest," said Langley Steinert, founder and CEO of CarGurus. “If you are shopping for a luxury car, there are substantial savings to be found by buying used. However, the story on used trucks is quite different. Recent demand has kept truck prices high, and the savings you might expect by buying a used truck will be much harder to find.”

We've compiled a list of the ten cars that have depreciated the most over the past year, and are thus much cheaper on the used-car market. Click through to see the used cars that can save you some serious coin.

2012 Cadillac SRX

If You Bought It New: $35,985 - $49,585
Fuel Economy: 17 mpg City, 24 mpg Highway

Price Drop Between 2013-2014: -15.5%

This luxury crossover offering from Cadillac went down in price 15.5 percent between 2013 and 2014. The SRX is a comfortable and capable CUV, complete with a load of standard features and handsome styling.

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2009 Cadillac STS

If You Bought It New: $46,845 - $57,895
Fuel Economy: 17 mpg City, 26 mpg Highway

Price Drop Between 2013-2014: -15.6%

The striking Cadillac STS is no longer in production, but still can be found on the used market. This luxurious ride dropped in price an average of 15.6% over the past year.

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2008 Volkswagen Passat

If You Bought It New: $23,990 - $39,200
Fuel Economy: 20 mpg City, 29 mpg Highway

Price Drop Between 2013-2014: -15.7%

The previous-generation Passat can be found for a good deal on the used car market right now, down 15.7% in price since last year, according to CarGurus. It's a comfortable, fun-to-drive midsize sedan.

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2009 Audi A4

If You Bought It New: $31,000 - $48,800
Fuel Economy: 23 mpg City, 30 mpg Highway

Price Drop Between 2013-2014: -15.8%

The sharp, comfortable and fun-to-drive Audi A4 is a good way to go if you're looking for a used luxury car. Prices on a 2009 A4 have come down 15.8% over the past year.

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2009 BMW 3 Series

If You Bought It New: $33,600 - $44,550
Fuel Economy: 18 mpg City, 28 mpg Highway

Price Drop Between 2013-2014: -16.2%

Like the A4, the 3 Series is a solid choice is you're in the market for a used luxury ride. Its handling dynamics are superb, and it's been dropping in price quite a bit over the past year.

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2008 Volvo XC90

If You Bought It New: $36,210 - $49,870
Fuel Economy: 14 mpg City, 20 mpg Highway

Price Drop Between 2013-2014: -16.3%

This spacious, comfortable and safe crossover is a great choice if you have a growing family. The 2008 Volvo XC90 has dropped in price more than 16 percent over the past year.

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2009 Nissan Altima

If You Bought It New: $19,900 - $29,380
Fuel Economy: 23 mpg City, 31 mpg Highway

Price Drop Between 2013-2014: -16.5%

Down 16.5 percent in price over the past year, the 2009 Nissan Altima is a family-friendly midsize sedan that gets solid fuel economy and decent power from its 2.5-liter four-cylinder engine. This car is a good choice if you're a commuter.

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2012 Mercedes-Benz E-Class

If You Bought It New: $49,800 - $91,500
Fuel Economy: 19 mpg City, 28 mpg Highway

Price Drop Between 2013-2014: -17.4%

That dream of owning a Mercedes-Benz might not be so far off if you're willing to get one that's a couple years old. The luxurious 2012 E-Class, for instance, has dropped more than 17 percent in price over the past year.

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2010 BMW 3 Series

If You Bought It New: $33,150 - $45,000
Fuel Economy: 18 mpg City, 28 mpg Highway

Price Drop Between 2013-2014: -15.5%

This slightly newer BMW 3 Series has dropped in price even more than the 2009. According to CarGuru's data, it has gone down 17.5 percent over the course of the past year.

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2012 Chevrolet Equinox

If You Bought It New: $23,530 - $30,970
Fuel Economy: 22 mpg City, 32 mpg Highway

Price Drop Between 2013-2014: -18.9%

The vehicle that has dropped the most in price over the course of the past year is the 2012 Chevrolet Equinox. This American crossover is roomy and versatile, making it a good choice if you have a small family.

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