FOR the past two years the Detroit motor show has been a dismal affair. But this year the parties were in full swing again. Helped by government bail-outs and with debt burdens lightened by bankruptcy, Chrysler and GM are back on their feet; Ford, the other member of Detroit's Big Three, is thriving. It took America's car industry 20 years and a world war to recover the three-quarters of production wiped out by the 1929 crash. By comparison, the aftermath of the latest recession has been surprisingly comfortable.

Ominously for the locals, though, the biggest splash on opening day was made by a Volkswagen saloon, which is to be built in a new factory in Tennessee. Europe's best big carmaker is taking aim at the heart of the American market for the first time in over 20 years. Its bold move is just one sign of growing fragmentation in a market once dominated by the Big Three and a small clutch of Japanese rivals.

The recession sent car sales in America skidding from 16.5m in 2007 to just over 10m in 2009 (see chart, below). Since then the ride has been fairly smooth. Sales in December were equivalent to an annual rate of 12.7m cars and light trucks (sport-utility vehicles and the like), the best unaided performance since September 2008 when Lehman Brothers collapsed and credit markets froze. Industry-watchers are predicting a 10% rise this year. The most optimistic forecast sales of 14m. Analysts at Morgan Stanley, an investment bank, point to an improvement in the creditworthiness of buyers which is causing lenders to loosen their purse strings. Americans are even buying big, expensive vehicles again.

The 2008 crash allowed Detroit to push through changes that had long been blocked by unions and timid management. Capacity was cut drastically: Ford alone closed 17 factories and reduced employee numbers by over 40%. GM ditched brands such as Hummer and Saturn to focus on Chevrolet, Buick and Cadillac, while Ford got rid of all brands except Ford and Lincoln. Health care for company pensioners, long a millstone, was transferred to union-run trusts. New workers can now be hired at lower rates than those ramped up by the United Auto Workers during the boom years. Alan Mulally, Ford's chief executive, reckons his company can compete on price with factories opened in weakly unionised southern states by Japanese, South Korean and German carmakers. Ford may have made as much as $10 billion in profit last year.

The Big Three have changed, but their home market has changed even more. GM may still be the market leader; Ford's trusty F-150 pickup is still the bestselling vehicle. But Detroit no longer dominates its backyard. For the Big Three now read the Magnificent Seven. Toyota, Honda and Nissan have been joined by Hyundai and its sister brand Kia in a fragmented market where seven manufacturers each have more than 5% of the market (see chart). And an eighth is trying to join the club.

Volkswagen retreated from America in 1988 and has since relied on cars imported from Mexico or Germany. But the slumping European economy and the success of its rival BMW's Mini brand has nudged the manufacturer to make a full-scale re-entry into what is still the most profitable single car market in the world (though China is now bigger in volume terms). VW and its Audi offshoot sold 358,500 cars in America last year. The firm's boss, Martin Winterkorn, aims to triple sales by 2018 and plans to spend some $3 billion on boosting the group through such things as marketing and opening more dealerships. The Passat being built at the new $1 billion Chattanooga factory is a slightly longer version of a car that sells well in Europe.

Competition is particularly fierce in this “mid-range” market, where Toyota's Camry, Nissan's Altima and Honda's Accord have long dominated. Since petrol prices first rose above $3 a gallon in 2005 Detroit has been trying to reconquer the modest car market instead of relying on sales of expensive, high-margin SUVs and other gas-guzzlers. Ford is bringing in slightly Americanised versions of saloon cars that have been successful in Europe, while GM plans to do the same with versions of its German-designed Opels. Chrysler will import Italian technology from Fiat as the ties between the two companies strengthen.

They will face an old adversary. Quality problems at Toyota led to $48.8m in government fines and a recall of 4m vehicles in America alone, cheering the firm's domestic competitors. Toyota's embattled chief executive, Akio Toyoda, making his first visit to the Detroit show, admitted that the firm “did receive damage”. But it would be foolish to underestimate the ability of the world's biggest carmaker to put its house in order: it still has the most efficient system for product development and manufacturing, even if it must focus for the moment on quality control. Mr Toyoda is attempting to inject some humility into the company's rigorous culture. For the first time it is offering customers discounts to increase sales.

The Japanese firm could learn a good deal from Hyundai and Kia. The South Korean firms suffered from reputations for poor quality when they entered the American market and relied largely on bargain prices to sell their vehicles. Under pressure from consumer magazines they gradually improved their quality and have won recognition from critics and customers. That jump in quality, as well as heavy marketing, has turned them into serious competitors. A glimpse of the next challenger came from BYD, a Chinese firm which showed off a battery-powered car and promised to unveil its much-delayed American sales network soon.

Detroit's home team was not without its own triumphs at the show. GM's plug-in electric hybrid, the Volt, won the coveted North American Car of the Year award, while Ford won the award for best truck. GM also unveiled the Sonic, a new small car with which it hopes to reduce its dependence on big pickups and other trucklike vehicles. In a market where success is harder to come by and failure will be judged harshly, they had better keep winning prizes.