Memorial Day weekend sales events haven't taken place yet, but already analytic firm TrueCar is expecting major growth in May sales, according to early projections for the month.

Automakers continue to sell new cars at a rapid pace, and TrueCar believes May will be the best month since May 2007, before the recession hit and vehicles sales took a plunge. The early projection is for 1.4 million units, which would be a whopping 32 percent increase over May 2011.

"Pent-up demand continues to fuel auto sales at a steady and sustainable level in May" said Jesse Toprak, vice president of market intelligence for TrueCar. "All major manufacturers will see double digit growth this month."

Chief among those is Volkswagen, which may have its best May ever on the back of strong sales for the Passat and Jetta. Honda and Toyota are expected to make the largest gains from a percentage standpoint, as May 2011 saw those automakers' sales dive due to the Japanese earthquake.

Drivers planning to trade in their car this weekend at a sales event should be sure it's in top condition so they can get the most value. Investing in a car tune up or minor auto repair can pay dividends if the dealer finds that the vehicle is in perfect condition when negotiating the trade-in price.