Santa Monica, Calif. - TrueCar Inc., a negotiation-free car buying platform, estimated that the average transaction price (ATP) for light vehicles in the U.S. was $30,634 in November 2013, down $198 (-0.6 percent) from November 2012; and down $164 (-0.5 percent) from October 2013.

November 2013's drop in average transaction prices was the first year-over-year drop since December 2010, when ATPs fell 1.8 percent.

Three automakers – Chrysler, General Motors and Toyota – all achieved record highs for their average transaction price in November, however.

"Relatively higher levels of discounting are being used to clear out 2013 model year vehicles," said Jesse Toprak, senior analyst for TrueCar.com. "We expect transaction prices to continue to stay in record territory in the short term, as long as the fundamentals in the economy stay positive."

In addition, TrueCar.com estimated that the average incentive for light vehicles was $2,507 in November 2013, up $17 (0.7 percent) from November 2012; and down $53 (-2.1 percent) from October 2013.

TrueCar.com estimated the ratio of incentives to average transaction price for light vehicles was 8.2 percent in November 2013, up 0.1 percent from November 2012 and down 0.1 percent from October 2013.