i had a big pile on my bonnet too one hot sunny day a few week back.
Washed it off with water cos I was at work no other stuff available, a big mark there. gutted I was. came back 3 hour later and the mark was not there any more. No one had touched it either, I dunno what had occured. Maybe the sun had melted whatever mark was left but it certainly wasnt there.
thought id had it with the 182 cos there was a mark on my dynamique that wouldnt budge at all from bird poo.
have you got a pic of the offending part of your pearl blue paint fixx? Renault paint isnt that strong really, mind dont suppose any is these days.
Ive even carried water around with me before now to get it off asap, needs to be like as soon as you see it, the mark on my dynamique was there less than 2 hours. The mark on my 182 what went away on its own was there less than 3 hours.
At the worst times of the year for birds, I always have some water with me. As for cats jumping on the car and scratching it not a lot I can do to stop that.