Key word "intended"! I'm willing to bet some from of rationing or prioritising will be put in place before it reachs $8/L. And at some point petrol becomes such a scarce commodity that many petrol stations cease to be viable businesses. Before that point, there will be days where some petrol stations simply miss out on what's available to go around.

Many petrol stations are already unviable businesses - if they have to rely on petrol sales (watch the Insight program I linked to earlier in the week).

They make their profit from selling food and other items, or from servicing cars - most of them make a loss on the fuel sale component of the business...

Actually I did, and I suspect the reality is that, yes, some independent retailers are making a loss on petrol sales for some of the price cycle, but I don't believe a petrol station would bother the hassle of maintaining itself as a petrol-selling business if it were truly making no profit at all on selling fuel for any period of time.
I have noticed a couple of local 7-11's rip out their petrol pumps. With petrol becoming more expensive, there could potentially be more viability in small local grocery stores and the like, which might be a logical market to switch into.