I want to know if anyone has some tips on model car crashes.
I have not done one myself, but have seen several on different layouts. I think that the most difficult thing is to come up with convincing damage to the vehicles.
If the cars are plastic use a soldering iron to melt the plastic. Just hold it close until the plastic gets soft then gouge it and crumple it up with a hard object. You can also just stick the soldering iron into the car to create gashes. When you are satisfied, drybrush some silver highlights along the edges to simulate bare metal showing. I did this with an HO hopper and it looked realistically dinged up.
Also under the crashed cars, paint some glossy browny-black paint in a puddle to simulate oil leaking. Also, carefully take a glass bottle you dont need and place it in a cloth bag or towel and smash it up into fine powder… sprinkle this around to simulate broken glass/winshields etc.
Hope this helps.
Ps- use caution… the melting plastic is very toxic… and glass cuts!