Nielsen Online’s latest Automotive Industry Overview shows that gas prices and the economy were key topics of online discussion in 2008. More than one million messages focused on gas, as consumers discussed strategies for dealing with a $4 per gallon price tag. The financial crisis and its impact on the big three automakers also fueled conversation, as consumers began looking into more fuel-efficient vehicles. Though alternative fuel/hybrid vehicles like the Toyota Prius, Chevy Volt and Ford Fusion hybrid generated substantial buzz in 2008, high MPG was only one hot …