Congrats!
Great to hear 20" wheels combined with (704) M Sport suspension does not feel like driving on bricks
I am a little bit worried as I ordered 20" 668M wheels and went with M Sport suspension.
Rears seem to sit a bit higher than other G30s i saw with m sport suspension but that might be due to the angle of your photos.
If you do not want to rely on dealer's word, you can VIN decode online and see with which options your car come from factory.