New car quality has taken a significant turn for the worse, reports auto industry tracking firm J.D. Power and Associates.

Owners of brand-new models or models that have been significantly redesigned are reporting more problems with their cars than they did in the past two years. Meanwhile, owners of cars that haven't been changed significantly have reported a drop in problems.

The results were reported in J.D. Powers' Initial Quality Survey, which polled 73,000 new car owners 90 days after they purchased their vehicle. Automakers pay attention to the survey results, using them to make design changes and boasting in ads when their brands perform well.

Many of the problems reported in this survey are not major quality issues but design flaws that make cars less appealing to customers. Twenty years ago, the IQS reported issues like door handles coming off in drivers' hands and frequent stalling problems. But overall quality has improved significantly, so the nature of complaints has changed over the years.

Most of the trouble spots reported in this year's survey are in engines, transmissions and multimedia systems.

These problems stem from two different things automakers are trying to do: They are attempting to make cars as fuel efficient as possible, tweaking engine and transmission software to squeeze out the most miles per gallon as possible. That sometimes leads to hesitations when accelerating or changing gears, J.D. Power says. Consumers are reporting this as a problem more often than in years past.

View Gallery: J.D. Power and Associates IQS Top Models Per Segment


Secondly, car companies are jamming cars full of new technology, in an attempt to win over customers who like new gadgets. But many of those systems don't function correctly and are not intuitive. Particularly problematic are the hands-free and voice-activation systems.

"Consumers are interested in having new technology in their vehicles, but automakers must ensure that the technology is ready for prime time," said David Sargent, vice president of global vehicle research for J.D. Power.

Lexus regained its No. 1 spot in the survey, which is lost to Porsche last year. Porsche fell to the sixth spot, behind Honda, Acura, Mercedes and Mazda.

Only two domestic automakers scored above average: Cadillac and GMC. On average, customers reported 107 problems per 100 vehicles. Ford came in below average, with 116 problems per 100.

Dodge was the worst-performing brand, and Suzuki and Mitsubishi were close behind.

J.D. Power said only seven all-new or redesigned models ranked in the top three position for their segments, compared with 17 all-new or redesigned models last year. One only newly-launched vehicle earned a segment award. The rest were existing models.

Check out the full rankings below.