Senate Majority Leader Harry Reid said lawmakers have reached an agreement to vote on a plan Thursday to add $2 billion to the “cash for clunkers” rebate program.

President Barack Obama said more than $775 million of the $1 billion in funding to finance the program has already been spent and will be completely wiped out by Friday if Congress does not earmark additional funds. The money spent thus far translates into 185,000 new car sales and is widely credited with reviving automobile sales.

The program, aimed at increasing automobile sales, allows consumers to take advantage of rebates up to $4,500 by trading in their old gas guzzlers for new compact, fuel-efficient cars.

According to Bloomberg News, citing Transportation Department figures, General Motors is the leader in car sales under the program.

GM “sold 18.7 percent of the cars purchased under the plan. Toyota Motor Corp., based in Toyota City, Japan, had the second-most sales with 17.9 percent and Dearborn, Michigan-based Ford Motor Co., was third with 16 percent. The [Transportation Department] released data on the [sic] each automakers’ share today, a day after providing a list showing that four of the top five models sold were made by foreign automakers.”

While GM accounted for the most cars sold, the bestselling vehicle was the Toyota Corolla. The Ford Focus was previously the most popular vehicle purchased under the program.

Reid said a deal was reached after lengthy negotiations between Democratic and Republicans lawmakers and he now believes there are enough votes to pass a bill to keep the popular program running through Labor Day. Republicans are expected to introduce at least a half-dozen amendments to the bill, such as one that would call for the federal government to sell its shares in GM and another that would put a cap on the income of consumers who take advantage of the program.

That amendment was actually proposed by a Democrat, Sen. Tom Harkin of Iowa. Under Harkin’s proposal, “only individuals with adjusted gross incomes of less than $50,000 or joint filers with adjusted gross incomes of less than $75,000″ would qualify for the program, the New York Times reported.

But Reid said he has enough votes to stave off changes to the program.

The deal was reached as the Senate begins a month long recess on Friday.