America's wheeling and dealing car salesmen have been twiddling their thumbs lately. The credit crunch is squeezing them from both sides -- making it harder for customers to get car loans and for dealers to keep money coming in.

"It has literally brought business to a standstill, to a halt," said George Mason, general sales manager at Momentum Volvo in Houston, Tex. "Banks have gone back to old-school lending."

On Monday General Motors said it would be giving financing only to customers with credit scores above 700 — the cream of the credit crop — and Mason said he sees even tougher trends from the banks he looks to for customer financing on Volvos, Jaguars and Land Rovers.

"Seven hundred used to be a very, very good customer," he told FOXNews.com. "Now a 700 customer has to have something close to 15 or 20 percent down in order to be considered for a loan."

Mason said a customer who wanted to buy a $60,000 Land Rover came in with $40,000 in cash as a down payment, and top financers still turned him down for the remaining $20,000, because he had a credit score in the 500s.

"We finally got him financed, but I had never seen anything like that before. People with marginal credit are finding it very difficult to find loans right now," he said.

Sales overall are taking a huge hit, and the dealership is reducing its inventory because it can't sell cars. Mason said the used-car business is doing better, but with the 2008 model year vehicles, "we're in trouble."

Banks are much more cautious now when it comes to financing cars, said Mark Schienberg, president of the Greater New York Auto Dealers Association. "If you came to lease or finance a car a year ago and you had a score of 650 on you credit score, you would be considered a second-tier customer. It's probably now a third-level customer."

Unlike the subprime mortgage disaster, the car crunch is also affecting the mid- and high-end of the market, said Michael Scarpaci, general manage at East Hills Auto Group in Queens, N.Y.

"It’s the guy that was making $200,000 a year last year who's now making $90,000 a year that's the problem," he said. They can't make the BMW payments anymore, so they're turning to used Chevrolets.

"The same customer who came in for a 2008 Chevy Tahoe or a Suburban, brand new, can get a pre-owned with anywhere from 10,000 to 15,000 miles for almost half the price," Scarpaci said.

East Hills Auto is also stocking cars that cost less. The average price before the credit crunch was in the $28,000 range, but now the dealership is stocking up on cars that cost between $15,000 and $18,000.

Dealers are having trouble getting loans, too.

"The banks are looking at dealers and saying if you're not really well capitalized as a business, we're going to look twice at you before we [pay for] your inventory of cars. For the business, it's gotten quite difficult," Schienberg said.

Slow sales mean that cash reserves are drying up, threatening the jobs of 60,000 employees at the 450 dealerships that are part of the New York association.

The first cut is usually advertising, which can run a small car dealership between $50,000 and $100,000 a month. But without advertising, the dealers can't draw in new business.

"It's sort of a Catch-22 situation," Schienberg said. "If we don't free up the capital for consumers to be able to buy cars and be able to do what they need to do as a necessity for their travel, it will be a real problem."

Even with slowing sales, some dealerships are still doing well enough to feel secure.

In San Diego, business isn't as good as it used to be, but it's not that bad, said Pavel Kofman, general sales manager of Rancho Chrysler Jeep Dodge. "Business slowed down about 20 percent, but it's still pretty good," he said. "The banks are giving out loans."

While sales plummeted last month because of Hurricane Ike, Gillman Honda Houston Southwest in Houston has seen business bounce back as people try to replace cars destroyed in the storm.

"I went almost 10 days with no sales. We lost serious money," said used car manager Richard Mahoney. But now, he said, "Hondas are selling. They're just on fire, because Honda is not in the truck market. The cars and the SUVs, I can't keep them."

Dealers are slashing prices and throwing out incentives, so if you can get a loan . . . "Strangely enough, it's a hell of a good time to buy a car," Schienberg said.