DJR Team Penske's Marcos Ambrose has been hit with a $5000 fine this morning, with $2,500 suspended.
The Stewards deemed Ambrose breached Rule E 1.3.6, which states that practice starts are not permitted during Meeting rides.
The fine comes after an investigation and admission by Ambrose.
The returning two-time champ was positive after yesterday's running on track and primary driver Scott Pye finished this morning's practice session in the top five.
While Ambrose's has been the only infringement handed down this weekend, the Stewards had an interesting start to the Wilson Security Sandown 500, on Thursday hearing a protest from Prodrive Racing Australia on Craig Lowndes' conduct at the last event at Sydney Motorsport Park.