It is possible to obtain benefit from both the rental vehicle excess insurance from Prosura and excess reduction from the car rental company, providing the claimed amount is not being reimbursed twice (please refer to the PDS for further clarification).
If you had an incident while in possession of the rental car and you had purchased both the car rental company excess reduction product and rental vehicle excess insurance, you could lodge a claim with Prosura for the out of pocket expense that remains after the car rental company's product had been applied.
For example, car rental company products often have an out of pocket expense (eg. reduced damage liability fee to $1,000 instead of $4,000) plus product damage exclusions (not covered by the car rental company excess reduction product) such as windscreen, under body and overhead damage and single vehicle accidents. The reduced financial liabilities and product inclusions / exclusions vary depending on the product purchased and which car rental company you hire from.
So, for example, if you purchased a car rental company excess reduction product where you were still liable for a reduced damage liability fee of $1,000, you would be able to lodge a claim with Prosura for the $1,000 out of pocket expense the car rental company charges you.
Full product terms and conditions are outlined in the Product Disclosure Statement (PDS).