Darn, I have to yank the handbrake way up even on an slight incline to get the car to secure itself. G8 thing or just my issue?

Mine locks the car down without much effort at all...

mine isnt hitting on much

Hmm i think maybe i should report this to the dealer?

If the G8 is like the previuos model Commodore, which I think it is, the park brake is a separate drum shoe on each rear wheel (separate from the rear discs).

This is why you can't pull handbrakies very well - the wheel locks completely.

I have to get mine retensioned every service on my 2003 Commodore, and you have to pull the drum cover off to do it.

Having said that, the VE/G8 may be different.