The plastic fascia garnish under the steering wheel on my LGT was scratched up badly by the previous owner, probably from having a lot of keys on the key ring that hit up against the fascia.
Anyway, I thought I'd try and clean it up a bit.
First, I lightly sanded all the areas that were scratched up, removed any dust from the sanding, hit it with a mildy abrasive polish. After cleaning off the polish it looked all smooth and tidy but the colour was now too light so then I hit it with some black boot polish. It came up like brand new and I was able to match the original colur pretty closely by just adding/removing the polish.
I wasn't really expecting this to do much so I didn't take pics, but if the interior plastic is black it's worth a try. I'll have a go at the area where the seat belt retracts against as this is in the same condition.
This may help others as the plastic seems to scratch fairly easily on Gen 4s