what car?
i assume a GTI...
first, check if your gearbox oil is under-filled...
when it is under filled and u are in such a steep parking like lowyat, the oil might not be enough to bath all the components.. gravity maaa..
and u will get overheat warning...
there is cases of GTI gearboxes being under filled from factory...
auto hold... lol
when u come to a complete stop on a slope, the hill hold assist will kicks in after a while...
to know if your hill hold function has kicked in or not, you just need to feel your brake pedal.
if your brake pedal hardened suddenly, thats the sign that the hill hold assist has kicked in...
once u remove your leg from the brake pedal completely, u got about 1 sec to hit the gas before u feel a roll back...
its a Passat, ok, i've never popped the hood of the car yet, gearbox oil is which part yeah? usually the auto hold works without touching the brakes, I think that is why the car rolled backwards... so need to press the brake to confirm it has kicked in la before pressing the accelerator I guess..