I promised to post the RTA answer re the Commodore crash. Here it is.
Philip,

the test was conducted in 1992 and was part of a series of tests to commission the crash test facility. The test was of the drive system, not the car.

The car was a standard 'second hand' car except that the tail shaft was removed. 300kg of sand ballast was placed in the footwells and boot and a ballast dummy (75kg) was placed on the rear seat.

The test speed was 100km/h into a solid concrete reaction block.

Colin Jackson
Crash Barrier Manager
RTA Crashlab
(02) 9830 1721

Regards Philip A