Bird poo etches into my red Golf within minutes, so has to be removed asap. It's not as etchy on the Morgans and our white Polo, but I always get it off before it sets hard.
The bugs were out in force in Scotland this year. Not been that bad for ten years. Removing any of this stuff needs hot soapy water in a spray and patience. A throwaway microfibre helps.
As a last resort you could clay bar the residue at the end.
I've tried fancy bug shifter and it's OK, but nothing special.
