Being cautious is good, over complicating it isn’t necessary. I understand you want to inform yourself but find reassurance that this is in no way anymore difficult then any other car.
So I installed these. The f30 won’t fit like some people say. The turn signal on the mirror is not the same. If I remember correctly the m mirror cap for the F48 F52 F39 F49 G29 have the same mirrors as the Supra. It actually helped me with the wind buffeting in conjunction with a buffeting fix...
Little too expensive IMO, plus I tend to want to modify my car by the time I’m a year or two in so a warranty is useless let alone an extended warranty
I'd imagine you'd just need to clear the caliper on the bigger 3.0 brakes. Probably the biggest liability. People run 18's and even 17's on their 3.0's no problem so i'm sure you'll be ok.
Mods? Mileage? Weather conditions? Any tune? What fuel are you putting in the tank?
Could be a million things, without the proper info it may be hard to diagnose here.
I had this happen sometimes on my old car, usually came down to colder weather for the car, or plugs.