For most Americans, buying a car is their second biggest purchase after buying a home. Given that many people now opt to rent instead of buy a house, maybe purchasing a vehicle is the biggest financial decision many people will make.  Are they ready to do most of the buying and paperwork online before they even get to a dealer?  Jesse Toprak, chief analyst with Cars.com thinks so.  "I think what AutoNation is offering will appeal to a lot of people," said Toprak who saw a demonstration of SmartChoice Express at an AutoNation dealership in Ft. Lauderdale, Florida.  Read MoreLarge SUVs register gains as gas prices fall  "Car buyers are tired of spending two or three hours in a dealership, this might be a better option for people used to buying so many things online," he said.  Here's how AutoNation's SmartChoice Express works.  Customers go to the AutoNation website and look at all the cars in the company's inventory. With 277 stores spread across America selling more than a half million vehicles last year, AutoNation believes it has the inventory to meet the desires of 95 percent of those looking for a new or used vehicle.  Once you find the model you want with the features you want, you can begin negotiating or haggling for the price you are willing to pay.  AutoNation will have staff standing by ready to negotiate, though the company believes the pricing it offers will be competitive and close to the final transaction price.  Once customers have settled on a price, they can handle much of the paper work, including setting up financing by working through the SmartChoice Express web site.  Depending on the location of the vehicle you bought, AutoNation will tell you when it will be at your nearest AutoNation dealership.  Read MoreUS auto sales expected to hit record high in 2015  If you have all of your paper work signed in advance, AutoNation believes it can have you in and out with your new vehicle in under a half hour. Those working trade-ins or who have specific issues they want to discuss with the dealer will take a little longer.
AutoNation is launching a new service called SmartChoice Express that aims to get car buyers in and out of the dealership in 30 minutes.