My
MK1 Leon had an after market CD changer in the glove box when I bought it.
I replaced the tape unit in the dash with a CD player and took the auto changer out. Only to find some Muppet had cut the original liner to bits to fit it. That would explain why it skipping over bumps!
As a temporary fix I cut up a beer box (I think it was Stella) and used it seal the end with a load of tape. That was 11 years ago and I never got around to getting a new liner.
I do sometimes get a comment about the cardboard in the bottom of the glove box - maybe I should have but the plain side facing the other way.
Also the Leon as the same dash as a MK1 Audi A3 which may give you more options if you're looking for a second hand replacement.