Bought my 2019 GT2 at Cerritos in July of last year. Buying experience wasn't too bad of an experience. Luckily at the time it was a buyer's market, plus they almost definitely had the car on the lot for awhile, and I was purchasing right at the end of the month, so they wanted to lock in a sale. The internet sales guy basically just gave me a number which was pretty darn good, and basically couldn't be beat by the other dealerships in the area. Kia of Downtown LA had the exact same car (same year, same trim, same color), but wasn't willing to come close to what I was offered at Cerritos, and the guy I spoke with was actually so shocked he basically said he should look at getting it himself.
Their service department is alright. Got my first oil change and also the recall done through them, which went fine. Prior to that though I took the car back because of some fit and finish issues -- namely this popping noise coming from around the doors when going over bumps, and a rattle in the sunroof, both of which were there since I bought it. With the sunroof they said they had to keep the car for a few days and outsource it to a place that deals with issues like that. I get a call a few days later and they tell me "the place said it's not the sunroof, but your sunglasses moving around in the sunglasses holder." What a joke. The noise is definitely from the sunroof, and when I said that, they said "there's nothing else we can do." Meanwhile, the service department of Kia of Downtown LA, and Car Pros Kia Glendale both acknowledged it was definitely the sunroof (unfortunately still dealing with the issue after it was only temporarily fixed twice).
That being said, they are not as bad as the service department at Kia of Downtown LA. I took my car there not just for the fit and finish issues, but the rotors needed to get turned (on a car with just over 100 miles on it, if you can believe it). One of the techs did not jack the car up in the right place on the driver's side and it basically made an indentation on the side skirt, so they had to replace it with a whole brand new side skirt (at least they didn't fight that they were to blame). That was a nightmare, as I could not get a hold of my tech at all -- multiple emails and calls. Not even the Kia Consumer Assistance Center could get a response. Was like that for weeks. I finally threatened to get it done somewhere else and would then come to them for compensation for the work, and then finally was able to get it taken care of).
Kia of Glendale has so far been the best Kia service department I have been to (although it did start off a bit rocky, but they immediately apologized, and ever since then it's been pretty good).