White adhesive (?) layer under wrap

[SpunkyGlory]

I bought a car recently that came with some orange wraps I wanted to remove.

I managed to remove the orange wrap using a heat gun but it's left behind a white layer, which I'm assuming is the backing adhesive as its not coming off easily.

Any tips to stop me going mad?

[Belle427]

IPA is usually the go to, petrol is pretty good too used sparingly.