Removing AutoAir paint



I'm painting a helmet and want to have another go at it as I'm not happy with the results thus far. I started re-scuffing the helmet and was wondering whether or not I have to get all of the paint off before I start repainting. I got about 30% of the helmet covered in paint at this point. Is it enough to scuff and apply a base coat or should I try to get everything off? I'm doing a 49'ers theme so there is a little gold metallic on there as well.

Oh yeah, I'm a n00b and this is my first project.
I haven't used auto air much, so not real familiar with it, but I personally would get most, if not all, of it off, just because I wouldn't want to take any chances with the adhesion, and I'm a bit of a purist when it comes to solid foundations. Realistically, as long as you did everything right the first time, you've probably got so little paint on there, that it should be alright. Scuff it good, hit it with wax & grease remover, and you should be ok if you don't want to sand it all off.
It was slow work using the red scuff pad but once I wet the pad with water it came off rather easily. Just needed to give the helmet a good wiping afterwards and I'll hit it with the degreaser before shooting paint again.

Unless you heat set the AutoAir , Just a mild soap and water will cut it off , At least 90% of it.