Floor Shifter Trim

a small piece of black Abs or Delrin should so the job. i used to pick up small pieces for projects like this from the remnant table at TAP plastics.
they are a west coast chain but recently opened a web store. www.tapplastics.com/‎
if you have any kind of plastic supply near you, you should be able to find a small scrap piece for a buck or two (or maybe even free) good luck.