DETROIT, Michigan - The 2013 North American International Auto Show has opened for news media previews amid booming sales and renewed optimism in the US.Dave Sergeant, an analyst with JD Power, said: "The mood is going to be pretty good. The industry is coming off a reasonably good year and 2013 should be even better."US vehicle sales are expected to rise to 16-million in 2013 year after jumping to 14.5-million vehicles in 2012, its biggest gain since 1984.BIG THREE SHOWCASEThe Detroit Big 3 (Ford, General Motors and Chrysler) are raking in huge profits after years of painful restructuring and taxpayers' support. The automakers' Asian and European counterparts are also investing heavily in the US as they jostle for position in the highly competitive market and look for a place to grow sales to counter slowdowns in China and Brazil and the collapse of European demand.Chevrolet unveiled its highly anticipated next-generation Corvette though the new model will have to compete with a new muscle car from specialty automaker Shelby at the show - not to mention its European rivals. The C7 is powered by an all-new LT1 small-block V8 capable of 335kW/450Nm and mated to either a seven-speed manual or a six-speed auto. Chevrolet claims the C7 is capable of sprinting from 0-100km/h in less than four seconds.Honda will display its compact SUV concept. Jeremy Anwyl, vice-chairman of automotive site Edmunds.com, says features until now reserved for top-of-the-range models such as heatable external mirrors and collision-avoidance technology, will make their way to mass-market models."Such features tend to be fairly profitable," he said, "because once they get into the mass-market they're not that expensive to install and consumers will pay fairly well for them." HYBRIDS ON RISE?Hybrids and electric vehicles will also be on display in Detroit. The US government will pass tough new emissions standards for vehicles.With hybrids and other alternative powertrains only making up 3% of the US market, automakers are going to have to work harder on their green-car pitches though there is hope that younger buyers could help push demand for green cars to the point where it would have a significant impact on the nation's fuel consumption.Joe Vitale, an auto analyst with Deloitte, said: "While they're not necessarily going to gravitate to and make a buying decision because of 'green' they do have a preference towards new technologies."We think this generation may be the generation that creates a tipping point to an electrified world."More than 50 new models will be revealed at the 2013 Detroit auto show.Stay with Wheels24 as we cover the 2013 North American International Auto Show in January.