Hi sam, you can inflict damage with a dremel or a knife, or even gently melt the part over a candle to bend it out of shape.
If youre really feeling brave you can use the thickish aluminium foil you get from takeaway food trays and by using the original part as a template, bend the foil around it. i used this technique on my general lee dodge charger dio so i could make it look like it had a front end impact and the bonnet (sorry hood!) and the wings were easily crumpled back.
Hope this helps!