I've installed Powerslide on one PC and I would like to copy the save files to another. I'd like to copy all files containing data about highscores, trophies and such. What is the best way to do this?

I've asked tech support and they've provided an answer. I shall post what they've said here as future reference for others:

The files that you should copy should be:
extra.pf
extra.pfb
extra.pfc

store.pf
store.pfb
store.pfc

If you have some additional custom settings file you should copy it as well.

thanks for your effort. i used to copy the whole game folder because i was too lazy to figure out which files i need.