The only way to fix the faded/scuffed plastic trim is to paint it with a vinyl paint. There are probably mobile guys around your area who will come and do it in your driveway. Google "plastic repairs" or "interior trim repairs" and see what comes up, or look in your local Yellow Pages (or whatever you have there) phone book under Plastic Repairs or Vinyl/Leather Repairs. Most of these guys can also tidy up your faded / tatty leather seat bolsters too.