I am just wondering if I am allowed to rent a car at the age of 20 with your company at St George Municipal Airport?
Look here to check if 20 year old drivers are allowed:-
The driver must have held a full driving licence for at least one year. At STEP2, click on the link "IMPORTANT INFORMATION' displayed to the right of the car photo of your choice. This will open another smaller window and if you click on "DRIVER" you will see what age restrictions there may be and any associated fees. Try a few different car models / suppliers, as they do differ. For example BUDGET say:-