ouch !
if your scratching it from cleaning your car, there's a problem with your method
i would pre wash, wash, decontaminate and correction if possible, apply polish and then a good sealant (like what i linked above)
just make sure you never use a brush on the bodywork or one of those wiper blade things
I dunno what the neighbour puts in their bird feeder but even a power washer doesn't take it off.