I was deciding between a Hyundai Kona and a Toyota Camry and also used Yelp. The two dealers of those brands in Clermont were far and away better than any other. After visiting Jenkins Hyundai in Leesburg and then Hyundai of Central Florida in Clermont, the reviews were correct. Great dealership and was $3400 cheaper than Jenkins.
Using this knowledge, I believe yelp is your best bet. Just doing a quick glance of Kia Dealers, Friendly Kia of New Port Richey has 4-1/2 stars from 68 reviews and Century Kia in Tampa has 4 stars from 35 reviews. The rest seem to be like you say, not great. That's what I found with Hyundai and Toyota. I prefer yelp over google and dealerrater, seems everyone is great on those two sites.
Friendly Kia - 31 Photos & 68 Reviews - Car Dealers - 5819 US HWY 19, New Port Richey, New Port Richey, FL - Phone Number - Yelp
Century Kia of Tampa - 41 Photos & 35 Reviews - Auto Repair - 4340 W Hillsborough Ave., International, Tampa, FL - Phone Number - Yelp
What I did after selecting those dealers was to email the dealer asking prices and a question about a color they didn't have in stock. One salesman in particular emailed me back and we corresponded for about ten days so by the time I visited the dealer I felt like I knew the guy. In the meantime I visited Jenkins Hyundai in Leesburg since it was closer and took a test drive to see if I really liked the car. Their sales manager gave me a offer and I had that in hand when I made my trip to Clermont. As it turned out, that offer was a joke. For one thing Jenkins has a $899 dealer fees added onto the price, Hyundai of Central Florida had no dealer fees, no dealer options (floormats were free, $125 at Jenkins) gave me a $500 Veteran discount, when I had the final price out the door with tax, tags and title, Central Florida was $24,400 and Jenkins $27,800 for the same car, that's it in my Avatar.