some event??

i was driving on the northern road near oran park this arvo, a nice little beetle went by was yellow with red rims on it it also has numbers and stickers all over it , then all the way to penrith there were spurts of cars with similar numbers and stickers on them lambos, porsches ferraris , toranas heaps of different cars was cool , does anyone know the bug and what the event is
t2

The car belongs to Rob from up the mountains and the cars are on the annual East Coast Targa