I’m a tiny woman who isn’t starting road rage, so what I do is just make the other person concerned. I’ve done this as a pedestrian and a driver.
It’s really easy, as a pedestrian walking past, pause slightly and drop your eyes to their front grill, tilt your head slightly and grimace. If in the car, point and sit up in your seat like you’re trying to get a better view of their car and do the same face. Look alarmed even.
I’ve seen multiple drivers pull over to check out their cars. At the very least it makes them take time out of their day for no reason - and inconveniencing dickheads is always fun - but given we’re in Australia, their imagination can take them to all kinds of places. What did she see? Is it still there? Is it in my car now???