220T/200T brake questions

Preambule
Couple of weeks of owning a 220T, I occasionally went to the 'Ring... 'Ring shall not be brake-abusing at all - on my previous 200 I could have done lap after lap with no issue.
But here, after a couple of laps with decent cooling cycles on the nearby roads, I started experiencing heavy wobbling under the braking. And after the trip it does not go away. I am a bit frustrated and wondering how will it be at, say, Spa, where the brakes are used way more heavily.

Questions:
1. Is it common for these cars or am I alone here?
2. What is a cure? Skimming discs? Replacing them?
3. Can it be considered a case for warranty - the car is just above 1 year old
4. RS monitor has a tip in it - to remove spoilers in front of the wheels. I doubt it can help, but has anyone tried? I haven't had a chance to have a good look from underneath, but it looks like these spoilers can't be easily undone. What is the process?

PS yeah, I know, big brake kit and all this stuff... But is there a sucess story with standard brakes? I'm not a huge fan of aftermarket mods when ones can be avoided. My 200 had the only mod of Quaife LSD - that's it for 4 years of ownership.