Because I had the vehicle over a year before it started happening. Doesn't get driven that much compared to my other cars. Brakes don't fall under regular warranty work and only have a short warranty period and low mileage. Not sure what the time frame and mileage is though.
There’s a way better chance your rotors just had some pad residue built up on them than your rotors were warped. Modern rotors rarely warp…it’s pad build up like 95% of the time.
An old school trick that actually works pretty good is to spray the rotors with water when they’re cool and let the car sit overnight or until you get a hood coating of rust on them then run out and do a few hard stops. The rust scale acts like sandpaper I guess.
It usually happens after I've used them hard a few times from higher speeds. If I do it once from 70+ it's fine but if I do a few quick slow downs from higher speeds it fades quicker than expected and shudders like they are warped.
I haven't tried the water and rust trick as I haven't heard that before. I've heard doing a couple really hard slow downs from high speeds usually knocks the buildup off but that's never worked for me.