if you have 2 cars and one is on gas, you can get them swaped over by a gas specialist and it will cost about 500, in QLD its a $2000 rebate, so you get $1500 to keep.

it was suppose to work out this way for me but the tank i had was too old so i had to pay 700 for a new tank, but was still worth it cos i was selling the other car.

so all up it still cost nothing and $800 to spend on whatever.