No, it's not possible. All rental cars in Australia have the steering wheel on the right.

In fact, however, based on my experience of driving on the "wrong" side of the road (in my case, on the right) in the US, continental Europa, etc, I'd say you'll find it easier if the steering wheel is on the right. Having the steering wheel on the side you're not used to, you will be constantly (even subconsciously) reminded that "something is different" - I find this helpful when driving on the other side from the side I'm used to. (It also, obviously, means that you're better placed to see the road and judge the likely movements of other traffic.)