Bought a 2020 GT with 65k miles on it a few weeks back. Yep, high mileage with rental use. Purchase included a 4 year 48k mile bumper to bumper warranty.

Today I went to change the plugs. The first three came out and looked ok but the 4th came out wet. The liquid has a definite chemical smell to it. Here are pictures. What does the wet plug mean?

Second issue: shifting from park to drive/reverse there is a weird noise. . It sounds almost like the the brake pads releasing . I’ve also notice some pretty jerky shifts in lower gears. Is this normal for a cx5?

Third issue: CARFAX showed front rotors were turned and new pads installed. Didn’t see a service record for rear brakes but dealership said they had been replaced as they had 90% left. I always get squeaking in the morning and they feel soft compared to other newer cars I’ve driven. Is this just a Mazda thing or is something wrong?

 

Wet plug can be any number of issues, none of which are good.
Shifting sounds a bit clunky as well, my 2020 is fairly quiet in that respect.
Mazda brake service tricky and requires specific steps be taken or it can cause issues with the electronic braking system.
Not saying that is what you have going on, but I would get it ALL checked by a qualified Mazda service dealer to verify everything is correct.
And yes, I agree on the brakes, they are the only week spot on this vehicle for me.
They do seem soft to me as well and are not up to the stopping grip I'm accustomed to.
But like I said, that could just be me, and I will be installing performance pads and probably rotors at my 36K service.
And performance calipers down the road as well, if the pads/rotors don't suffice for me.

 

Changing the filter and fluid in the transmission likely would improve the shifting and noise. An often ignored
maintenance item.
Where was the plug wet at? The external ceramic and hex nut may just be left over from engine bay cleaning.
Wipe out plug hole and clean plug and keep an eye on it.
I defer to Lobstah on the brake issue.

My 2¢

 

Bring it back and use that warranty you bought. Spark plug looks like it has oil on it, that's not normal. Shifting between gears should not have that sound, also not normal. Low-speed jerk I've heard there may be a TSB for it, dealer should investigate for you. Brake noise in the morning that goes away could just be a very thin layer of surface rust on the rotor that develops overnight and gets scraped off when you drive in the morning. Did they check fluids when they did brakes? maybe you need to top up brake fluid. or it might be time to change it if it's never been changed before. This would not be covered by warranty, but the other things should be in a bumper-to bumper warranty. If they don't, you wasted money on the warranty!

 

The photos show the fourth plug to be wet on the engine side, so it is not from “engine bay cleaning”. Since the other three look okay, the wet plug may not portend well, although the electrodes and insulator don’t look bad.

 

I am in close to the same situation as you. I bought a 2020 ex-rental car. I immediately noticed transmission/jerking issues. I had an audible squeek from 3rd to 4th gear and erratic shifting in any gear under 4. So far I have had my transmission and a wheel bearing replaced... with more issues still being looked at. Ride that warranty as far as you can.