That Micro Prime stuff sounds like it might do the job, although it's difficult to know for sure.
Supernatural Micro Prime contains ultra-fine microabrasives to gently clean and prepare paint, removing fine swirls and contaminants
Righty, depending on how much time you have, you can do the following.
G3 from halfords WILL remove the stain, just depends on time you spend, anywhere up from 2 hours will about do it. If you don't have the patience, but have some money spare (and a fair amount) some Autoglym Intensive Tar Remover will do it (be warned, this stuff can burn your skin but will remove the stain), or some of This stuff will work too
Ha, I have those all over the car. The most annoying ones were actually in the lexan headlamp lenses! It is indeed suncream. I dealt with the headlights by using a machine polisher and cutting compound - the lenses were faded badly anyway. Not any more! :)