Steering lock ADR

[Outwest34au]

You need a lockout of either "Steer vehicle/Engage forward drive gears/Release a brake"
If you have an auto behind your LS3 it may be possible to wire in through a master solenoid off your immobiliser 3rd function. I am not familiar with the way the autos in them work so cant say for sure.
Some sort of solenoid activated locking pin along the lines of a reverse lockout solenoid maybe if you have a tremec, maybe a reverse lock-in setup???
A solenoid operated stop on the brakes? Possibly like a line locker solenoid to make the brakes "ON" and unreleasable unless activated by the immobiliser once again. The brake lock would be pretty easy to do.

Even though I am retaining my steering lock I was reading ADR 25/00 - ANTI-THEFT LOCK last night and pondering possible options if you went the other methods.

[Rebel1]

Some of the guys have wired the steering lock/ignition on the column and a dash mounted start button together. ie.You turn the ignition key to the start position (steering lock is then disengaged) but the starter solenoid active wire is via the start button, not the ignition switch.

Still leaves you with the column key which is maybe what you don't want.