This is a two part question:
If Bardock and King Vegeta are dead, do they ever make appearances in HFIL or Upper World? One would think that either Goku or Vegeta would want to pay their fathers a visit.
Do Goku or Vegeta ever mention their fathers once during the entire anime?
I don't recall any of this. Feel free to include the manga if anyone has that much knowledge on the matter.