I haven't built one but have a good mate who did build and test fly his CX4. It is currently for sale. I have attached a link from the CX4 community which shows all the builders and flyers in Oz. Best of luck, they are a great looking aircraft.
I am looking at buying a ‘19’ registered aircraft which currently has an automotive engine in it. I would like to replace the engine with another automotive engine which I rebuilt myself. Would this allow me to carry out my own maintenance? I am a qualified engine rebuilder.