What is a General Security Agreement (GSA)?

A GSA is a security interest over a company or an individual.  

This security is perfected when it is registered on the publicly view-able Personal Property Security Register. 

It will accompany a loan agreement and allow the lender to take control of the asset which the GSA is registered over.  In the case of a company this would be the appointment of a receiver.

A company may have several GSA's registered over it but the first GSA holder takes priority in enforcement and collection.

Can I borrow on the value of a vehcle owned by another person?

This is possible but the person who owns the vehicle must also guarantee the loan.  This sort of loan fits into the guarantor loans catergory.

Can I use GST as a deposit?

If the vehicle you are purchasing requires a deposit that you are struggling with perhaps the GST could be put into the purchase price when it is received after settlement.