I used my heat gun and picture hanging wire (plastic kind). Acetone removes the residue in seconds. Just make sure you move the heat gun / hairdryer back an forth to warm up the area..don't burn your paint.
It literally took me all of 20 seconds in the middle of an 80 some degree day while I was filming it lol. No residue really left behind either, but that might be partly due to the fact my car was only 4 months old at the time. All that black plastic needs is to sit in the sun and it'll heat up good enough. Had one friend of mine do it on a 70 degree day.