As NADA Used Car Guide reports that used-car prices are expected to slide in June for the first time this year, dealers may potentially be seeing an influx of trade-ins in the coming months.

In a Tuesday report, Forbes’ Jim Gorzelany cautioned buyers it may be time to “update your holdings,” or trade-in a vehicle as resale values are predicted to take a hit.

“If you’re one of those owners who wisely regard your car as an investment, the value of which should be preserved and leveraged as carefully as any other personal equity, now may be the time to update your holdings so to speak,” Gorzelany asserted.

As NADA UCG predicts used-car values will decline by about 2 percent, while truck values will fall by about 1 percent or half of the amount of cars come June, consumers may begin to take note of the changing environment.

And some of the more popular compact, fuel efficient cars, such as the Toyota Prius — expected to fall $900 this June — are expected to take the biggest hit.

And if consumers don’t take note of the shifting market place, they may find it harder to purchase a  new or used unit down the road.

“Lower resale values mean new-car buyers will get less for their existing vehicles in trade, meaning they’ll either have to come up with additional cash out of pocket to reach a higher down payment or make higher monthly loan installments,” Gorzelany reported.

To see the full report from Forbes, see here.

First Decrease in Used-Car Prices for 2012

Delving more into NADA UCG’s predictions for the coming month, the organization reported that after prices for used cars saw double-digit gains from January through May, it reported Tuesday that rates are expected to hit the brakes come June.

With prices on many popular used compact and midsize cars predicted to drop up to 5 percent month-over-month, NADA UCG explained some reasoning behind the sudden dip.

Jonathan Banks, NADA UCG senior analyst, noted, "The trend of rising prices for used cars will reverse course in June because of declining gasoline prices combined with a normal seasonal slowdown in consumer demand for used cars.”

Specifically, used-car values will decline by about 2 percent, while truck values will fall by about 1 percent or half of the amount of cars, according to the June edition of the NADA Official Used Car Guide.

Moreover, prices for used compact and midsize cars will fall by an average of 2.4 percent, with many units seeing even bigger declines.

Hybrids Expected to Slide

And after high fuel prices left many gas-sipping units in high demand with prices soaring, many of these compact vehicles will fall back to more normal levels in June.

"During periods of rapidly changing gasoline prices, values of hybrid vehicles become more volatile because consumer demand for hybrids rises and falls along with the price of gasoline," Banks added.

For example, the 2011 Toyota Prius Liftback 5D is predicted to fall $900 in June, after increasing in value by $2,350 from January through May, NADA UCG reported.

"Prices on the Toyota Prius will drop even more dramatically in June," Banks said. "Rapid depreciation for hybrid vehicles is not uncommon after surging gasoline prices reach a peak and then begin to quickly fall." 

And in looking ahead to July, NADA UCG expects this trend to continue among small and midsize cars.

“The NADA Used Car Guide is forecasting that depreciation for small and midsize cars, which experienced the greatest appreciation over the first part of 2012, will see values continue to drop sharply,” officials concluded.

NADA UCG also provided the following chart to illustrate the used-car price slide expected this June: