I've had several difficulties with my Suzuki. I believe the fault mainly lies in Carmax, though.
I've had the O2 sensor replaced several times (all under Carmax's warranty) at the insistence of the service light.
At about 68k miles, I had some very annoying wiring difficulties that caused my windows to get stuck. They would get stuck in a position and not move and then for some reason they would move again, only to get stuck again. Carmax successfully repaired this issue by replacing the wiring in all of the doors.
Then, the major problems happened. I had the strangest issue that I couldn’t find anyone that would understand it. Carmax said the clutch was going bad (the clutch happened to not be covered by my warranty), but I disagreed. After the engine was hot from driving on the freeway for a few hours, the car would die as soon as I hit the clutch (to exit the freeway). I finally figured out that this only happened when my air conditioner (AC) was on. If I turned the AC off while changing gears, it wouldn’t die.
At the same time I started noticing that the engine was using up too much oil. Carmax decided to replace the transmission with a similar year and miles, and it seemed to be fine… for awhile. Carmax apparently didn’t do a good job putting the transmission back and I was actually destroying other parts of the engine as I drove it. I took it to another repair shop and they found quite a lot wrong with what Carmax did. The warranty company agreed that it was a bad job and we paid the difference for a new transmission to be put in it. This repair shop did a much better job, but I didn’t find out until a few months ago that my 4x4 doesn’t work anymore. (What a pain to find that out while stuck in the middle of a huge mud puddle!)