Stick one of them nodding dogs/characters on it!! lol
On a serious note, not sure how you can get the sticky stuff off without hurting the dash. You dont want to rub too hard in case you make a smooth area on the dashboard!
Maybe someone else will have a better idea!
Sorry Im not so helpful!
Assuming this is not superglue or Araldite Generally nail polish remover (think it's Acetone )is pretty good for stuff like this but BE CAREFUL and test on an out of sight area for colour loss etc. Failing that some hot soapy water and a bit of elbow grease

. Other options although never tried just picked along the way on various sites in the past (maybe mask around the area too to protect other parts of the dash):
- hair dryer and sharp spatula - effectively scraping although be careful not to damage/scratch the dash and then maybe
- WD40 or LPS (liquid penetration)
- Lighter fluid - although don't have a fag at the same time
- Mayonaise - yes the stuff you put on your sandwiches - apparently this has natural adhesive removing properties
- Rubber cement thinner - try an art shop
- Other option is to google, god knows what other stuff is out there but a good starting point is trying to understand exactly what it is. Whoever did this install should be shot!
Just a disclaimer - In offering such advice I am not responsible for your actions in carrying out any of these option and resultant condition of your dashboard
