I have recently applied through Macquarie and still in the process of approval. I have been informed by the rep that they can lock in the interest rate @4.99% for 6 months (3 months plus 3 months renewal), if you do not get your car within the 6 months period your Loan approval will be expired and you need to start fresh and reapply submitting all the documents again with the interest rate at that moment.
May I know when did you get your finance approved and how many days did the approval process take ?