If any item of equipment used in a business is sold, then 1/11th of the amount received must be remitted to the ATO and a valid tax invoice must be provided to the purchaser (e.g. car dealer).
Note: A common error in GST returns is failing to remit GST when a vehicle is traded in for a new business vehicle. Please be aware that as well as claiming the business portion of the GST credits on the acquisition, you are also required to send 1/11th of the trade in value to the ATO (assuming 100% business use).