my car has a smal dent, i already pulled it but there are some visible remnants of it, i want some kind of filler that isnt too rigid, i heard bondo can crack

There is a body filler for plastics. I forget what it'* called but it'* pretty flexable. It comes in a dual tube container with black and white stuff in it. You press it out and mix it up. It takes a while to cure too.

Get a 2 part plastic repair expoxy, 3M as well as some other companies make them, they come in all different types from rigid to semi rigid.