You tell us about the car
The rego, the make and model, roughly what it has done, and anything you already know is wrong with it. That last part is the one that matters most, and it is the one most sites do not bother asking.
It takes about two minutes. There are no photos to take, no VIN to go and find, and no account to create. Your name and number are the last thing asked, not the first — so nothing is sent anywhere until you decide it is.