An unexpected reignition of interest in luxury cars has led BMW, Mercedes-Benz and Audi to add more shifts to its production facilities in an effort to meet the increased demand.

According to BusinessWeek, Mercedes-Benz is adding 1,800 temporary workers and adding Saturday production at its factories in Germany, which are responsible for the E-Class convertible, GLK SUV, and SLS AMG sports car.

Its countrymate BMW is following suit, adding 5,000 temporary workers to keep up with rising sales. BMW recently announced that their 5-Series was sold out worldwide, another sign that this sales surge was not predicted by the car companies.

"The recovery in luxury-car demand has been a bit faster than expected as confidence returns," Colin Couchman, an analyst at IHS Global Insight in London, told the news source "The growth is sustainable, because these companies have continued to invest in new products and expand into new markets."

Luxury cars can be quite pricy when bought new. As the economy rebounds, those who find themselves with a little extra money to spend might want to search for a late-model used BMW or Mercedes at a pre-owned dealer in order to avoid the inflation that occurs at new car dealers.