New more-complex transmissions designed to help automakers improve the fuel economy ratings and infotainment systems oriented toward helping better integrate smart phones have caused reliability problems for automakers, according to Consumer Reports' 2015 Annual Auto Survey.

Consumer Reports also released its five most and least reliable cars. Least reliable vehicles included the Fiat 500L, Ford Fiesta, Jeep Cherokee, Nissan Pathfinder, and Chevrolet Suburban/GMC Yukon XL. For the first time, Kia surpassed Honda and Hyundai finished ninth.Lexas, Toyota, and Audi were named as the three most reliable brands.

Consumer Reports has also pulled its recommendation for Tesla's Model S after owners complained about various problems, including the automatic door handles.

The outlet's annual report cited problematic transmissions such as a dual-clutch gearbox, continuously variable transmission, or eight- to nine-speed automatic.

The Dodge Dart's six-speed dual-clutch transmission and the nine-speed automatic and eight-speed dual-clutch transmissions are responsible for many of the problems reported in the new Acura TLX, hurting their reliability ratings even more.

Ford's powershift six-speed automatic showed a small difference in fuel savings over traditional manual transmissions in the 2011 Fiesta and 2012 Focus.

Infotainment systems were another cause for concern. The survey singled out Honda's AcuraLink, Cadillac's CUE, and Infiniti's InTouch systems amongst the most problematic infotainment systems. Common complaints were that the system was either unresponsive or crashing the touch screens, or the consumers' smartphone wouldn't pair to it.