Hello
the surface must be totally free of any uneven spots or adhesive, basically you must never know that it had been flocked before. Not the new you want to hear I know buts its the only way to get a quality finish after being re-flocked.
For the price of another dash it may be more economical to just buy another.
If you need any help just pick the phone and get in touch as we are will try and help best as poss.
(GT - cheers for the shout out)