Income doesn't matter where you get from.
You should prove documents you work full time.
Get letter from your taxi owner/ taxi management including their contact details and your working hours/ your shift and how much you earn...all in details.
Attached your records if you have pay slip / records shows taxi number, fuel you fill, mileage etc.- Make a summery shows you work 35 hours
and also, Tax document shows you paid GST & work to ABN.
your income should prove at lease to work 35 hrs per week.
if you get payments to Bank Account you should give bank Statement. ( be careful your address in BS ,if it shows different to regional area)
If you have issue to prove documents you can give Statuary declaration in front of JP.