i thought you knew geography
look north from brazil and you will see a large continent with alot of money i think you may even live there! The latin americans main route to europe is through the US, then again you have drivers with rich families or large sponsor backing who could afford to go race in the UK ie Ayrton or even Rubens !
and Brazil while it has its poverty also has its fair share of rich people! the gap between is just larger than most western countries
Australia is isolated from the rest of the world and its open wheel racing is almost non existant with only "small" series of formula ford. Touring car racing is where the money is at in OZ. There isnt alot of money sponsor wise to go race overseas as most australian sponsors wont get anything in return with a driver racing in a lesser euro open wheel series as would get no coverage in australia and the companies who would be willing to sponsor are not based in europe so local spin off sales would be non existant. Webber almost had to come home a few times if not for financial assistance from friends or getting sponsorship money ie fosters aussie beer (big in UK wont even see a true blue ozzie drinking it though
)
although with team australia in the champ car and atlantic series there is the main route which will help australian drivers race open wheel internationally and not let their talent go to V8 Supercars where the rest of the world will not see their skills.