On this subject. I'd have to say you have to say hello. That's a given. You usually can't just come up & leap into conversation.
For me personally, it's more impressive when a guy comes up & doesn't mention me or anything about but says "Hey, nice car, what all is done here? O ya? Who did it? O you did? Wow, impressive... what do you have planned?"
I love conversations like that.
Shows me that the guy is NOT just coming up cuz I appear to be another pretty girl, but b/c I appear to be an unusual pretty girl w/talents that few other girls have.