I have a 2018 mazda cx9 gt, 68,000 miles. Never had a prob, well maintained, love this car.......went to family up in ohio, 500 mile trip one way. We were up there a week and evening before heading home, i noticed puddle under car and figured it was ac condensate, although i must have sensed puddle was too far to center of vehicle......i dont know why i checked, but it was coolant. I couldnt believe it. Coolant leak was dripping off splashshield under car at oil pan access cover. Checked overflow resevoir and it was really low. Went down to local autozone and purchased fl-22 asian green coolant and topped coolant off to correct levels. I jacked up car and removed access panel. Coolant droplets everywhere around area and i could tell leak was coming from above, back side of engine. Couldnt see up that far with exhaust, turbo, etc. in the way.tight up there! Car never got hot and runs/idles perfect. Oil was changed just before the trip and looked great. Long story short , i drove it home the next day after local dealership wanted 5 days before he could even look at it, even after my vacation trip nightmare story(yes, i will share my story with Mazda and their dealership shotcomings when i get through this mess) Drove it home next morning...70 to 80, even using ac at times, watching the coolant temp and it ran perfectly all the way home. I called dealer that afternoon when we got home and he said to bring it in next morning. I brought it in the next morning and that afternoon they called me and stated it was a cracked head. I have an extended warranty for 8 years, 125,000 miles i originally purchased with the brand new vehicle. Service rep told me Mazda wanted block changed too and was going back and forth with warranty rep. Extended warranty wanted to inspect and 3rd party inspector will have looked at it it by end of Monday so we will see how it goes. I have purchased 4 new mazdas in the last 12 years and am a bit shocked by this problem. Glad i got it home without incident, but has been a painful experience and i hope this ends well. I have been looking at the competition for the cx9 on line all weekend and you know, i just dont see anything out there that checks all the boxes for my needs like the cx9. Monday i should know more and will report....