"Hi... I'd say something hit it from behind, something relatively soft, and since there are no visible scratches, it could have been something like a Jeep with a spare tire mounted on the back, or a truck with rubber bumpers on the loading edge."
I find it relatively unlikely that there will be vandals and, consequently, more damaged cars. It's questionable whether filing a report would be worthwhile in that case.
By removing the plastic wheel arch liner, you should be able to access the dent from the inside.
If it were my car, I would proceed as follows:
- Apply oil to the inner side of the fender, from the bulge to the edge, to prevent any plaster from sticking.
- Apply a layer of 2-3mm rubber (e.g.,...) over the plaster. Insert a rubber hose (or a similar flexible object) coated with oil into the fender from the inside, and then mold the original shape next to the dent.
- Warm up the dent thoroughly with a hairdryer, being careful not to cause the paint to bubble.
- Cut the shaped rubber-gypsum sausage to the appropriate size and press it from the inside against the bulge.
- To stabilize the plaster, add wood wool or similar fibrous materials directly during mixing.
Alternative:
- Use a tennis ball to apply pressure from the inside against the center of the bulge.
- To prevent the paint from cracking easily, warm it up with a hairdryer.
It might still be necessary, after the initial dent has been pushed out from the inside, to use a tennis ball from the outside, pressing gently on two small raised areas just above and below the original dent, to push them inwards and make the surfaces flat again.
Does anyone have anything better to offer than my two schnapps ideas?
Best regards and good luck, Rainer.