Want to trade in your pile of crap and get something purdy and of course, more environmentally friendly? Well, you better do it now because the U.S. Department of Transportation will end their Cash for Clunkers program on Monday.

An official from the Obama administration said that all valid transactions under the federal trade-in program must be submitted before 5 p.m. PDT Monday. The Department of Transportation is advising consumers and dealers heading into this “wind-down” period to only agree to deals in which all of the necessary paperwork has been reviewed and approved. Get more information on the Cash for Clunkers program here.

“This program has been a lifeline to the automobile industry, jump-starting a major sector of the economy and putting people back to work,” U.S. Transportation Secretary Ray LaHood said in a news release. “At the same time, we’ve been able to take old, polluting cars off the road and help consumers purchase fuel efficient vehicles.”

Congressional officials announced today that the government plans to suspend the “cash for clunkers” program since concerns were raised that it could rapidly run out the $1 billion in rebates for new car purchases.

The Transportation Department called lawmakers’ offices to alert them to the decision to suspend the program at midnight Thursday. The program offers owners of old cars and trucks $3,500 or $4,500 toward a more fuel-efficient vehicle.

The congressional officials spoke on condition of anonymity because they were not authorized to speak publicly. A White House official later commented that officials were taking a closer look at the situation, but reassured auto dealers and consumers to have confidence that transactions under the program that already have taken place would be honored.