J.D. Power's Initial Quality Study scores reflect the number of problems reported per 100 vehicles over the first 90 days of ownership. Across the industry, new-vehicle quality improved for the fourth consecutive year and has reached its best level ever, J.D. Power said.

In it's second year as an independent brand, Genesis rose to the number one position in the J.D. Power 2018 report of new-vehicle quality.

Genesis offers two luxury models- the G80 & the G90. Of the two, the G90 is 2018's highest ranked large premium car in quality. 

SegmentHighest RankedOthers Ranked
Large Premium CarGenesis G90BMW 7 Series, Mercedes-Benz S-Class

For four years in a row, Kia has been the top-ranked mass market brand. Kia also received two awards for their 2018 Kia Rio and 2018 Kia Sorento!

SegmentHighest RankedOthers Ranked
Small CarKia RioNissan Versa, Chevrolet Bolt
Midsize SUVKia SorentoHyundai Santa Fe, Ford Explorer (tie), Nissan Murano (tie)

Hyundai's 2018 Tucson received the accolade of Highest Ranked Small SUV! 

SegmentHighest RankedOthers Ranked
Small SUVHyundai TucsonKia Sportage, Mitsubishi Outlander Sport

Sources: http://www.autonews.com/article/20180620/RETAIL/180629995/genesis-kia-hyundai-top-jd-power-initial-quality-study