Despite a few winter storms and an underwhelming December, automakers on Friday released sales totals for 2013 showing a healthy return to normalcy. Between new models, pent-up demand and cheap credit, carmakers and their dealers sold some 15.6 million cars and trucks last year, a jump of just under 8 percent from 2012.

Yet the biggest movers weren't mass-market pickups or SUVs, but luxury vehicle brands from Cadillac to Lamborghini, many of which set sales records and sold every vehicle they could build or import last year — and only see more to come in 2014.

It's important to note that no one has a red-line definition of the luxury car market; the average new vehicle price of $32,920 in December would count as a luxury purchase for a majority of American households. The old bulwarks of branding don't hold sway either, not when Mercedes offers a front-wheel-drive sedan (the CLA-Class) with sticker prices less than a fully loaded Ford Fusion.

2013 U.S. luxury vehicle sales

Even accounting for some downmarket movement by a few brands, the boom in luxury models stand out. The two fastest-growing American vehicle brands in 2013 were Cadillac and Ram. Audi, BMW and Mercedes-Benz all set new records for U.S. sales in 2013, and smaller, more exclusive makes such as Jaguar, Land Rover and Porsche lapped the market's overall pace. Even Rolls-Royce, that traditional arbiter of the elite whose cars start at $260,000, reported a 60 percent increase from 2012 tallies. (The only high-end luxury brand to post a sales decline? Ferrari, which announced several months ago it was limiting sales to keep itself exclusive.)

"We're seeing much more confidence, with much more conviction among customers about the future of the economy, more optimism and enthusiasm," said Kevin Rose, sales and marketing director for Bentley Motors, whose U.S. sales increased 28 percent last year to 2,964 vehicles.

You don't have to have a day trading account to find the source of much of the wealth pouring into new vehicles. Stock-market gains often drive car sales at the high end, and in a year where Wall Street stock indexes had their best results in more than 15 years, it doesn't take much of that money to produce a waiting list at the luxury-car dealership. (Not to mention record corporate profits and the boom in oil and gas mining that lets automakers like Bentley find new customers in places like North Dakota, where the picture above was snapped.)

That little of those gains have translated into higher hourly earnings for most working Americans hasn't really worried the auto industry to date, thanks to millions of customers who needed to replace worn-out rides for basic transportation. Those shoppers could keep coming in 2014, although rising interest rates could put some brakes on their buying power. Meanwhile, the major luxury brands have plans for growth from their record highs last year. Whatever the mood might be in the middle of the market, there's a raging party in the penthouse.