I had stickers from the tracks I'd actually driven the car on in my E46. I don't think I'd even put those on my E90 until I've driven them in that car.
They're a bit like the stickers the fighter pilots used to put near their cockpits for confirmed kills...
Current: '11 SpaceGrey 328i XDrive
Gone: '07 SilverGrey M Coupe || '08 SparkG M3 || '01 LSB M3 || '01 TiAg 330ci