I have 260,000 miles on my 2007 Mazda CX-9 Grand Touring. I am in medical sales and put about 3k per month on it. It has been a great car. I have had to replace the wheel bearings a few times. I have a feeling the root cause was the lower control arms which were recently replaced via recall. I have had the A/C drain issue a few times, learned how to unglog it myself. Had the rear A/C blower kick on when the key is turned off problem, dealer fixed this problem. I replaced the shocks and struts at 200K. I replaced some belts and hoses at 200K because it was recommended at 150K, they looked fine to me. I service the oil with full synthetic every 6K miles, change the air and cabin air filter as needed. Flush the transmission every 60-70K. I have flushed the coolant once, just for the heck of it. Not much more. Had to replace the door handle unlock button, wore out and fell off. My SmartKey works fine, but I lost one. I tried to replace it, and 2 different dealers could not program a new key to work with my car. They wanted to replace the whole smart key system for $5k I think, I had them cut me a insert key, which is my backup still only have the one working smart key. I've done Alignment, Tires and brakes as needed, usually around 80-90K.
Yesterday my drivers side HVAC stopped blowing cold. Passenger and rear is fine. I can see the actuator motor working on both sides (right of steering column & left of glovebox), but no cold air from the two drivers vents(dunno). I brought it to the dealership which I believe have VERY mediocre mechanics, but do have access to all service bulletins. They told me that a flap door was stuck inside of the heater core under the dashboard. They want to replace the entire A/C-Heater assembly for $3,900 labor included. They gave me an $1,800 option with used parts. With my mileage, my car isn't worth more than $5K and I need new tires, a brake job and transmission service. I am taking her for a second opinion from a local mechanic shop. I am not sure if I want to get this done. It may be time to get a new vehicle. It'll likely cost me close to $3,000 to get everything fixed and maintained for the 300K mark. However, I am concerned that the dominos may be starting to fall. I don't want to put a lot of $$$ into this car if it doesn't have a lot of life.
I invite your comments and opinions. Cheers!