Hey mate, Try just using normal water to clean the headlight, then towel dry it. Rub it alot so that there is nothing left on the surface. Then use Packmate double sided badge tape from Supercheap. Cover the whole underside of the eyelid, and be careful when fitting, just sit the eyelid on and check they are both level, cause once you push down on this stuff its not coming off easily!
I thought the same idea, to clean the headlight, and for that i tried a small bit of metho. DONT USE. it started to effect my plastic. So thats when i went for the towel and normal water solution. They are still on months later and not going anywhere, and can withstand 160kmph + speeds
Packmate is the brand, trust me get that. Not 3m. I spent heaps on the 3m stuff too, and it was useless!