I now have a peugeot partner van for work, there are some deep scratch's on the plastic back bumper that I want to tidy up. I tried sanding the bumper first and I did manage to get most of them out but some are going to need filling. Have I do get a certian type of filler for plastic or will any type of filler do the job?

I am planning on painting it black with a rattle can tomorrow so all advice would be great as I have painted some small bits in the past, but never used filler before.

Thanks
Johny.