LOL I'm surprised, I thought Americans generally liked our cars and considered them cool, compared to the mundane, boring ass ones used in the US. e.g. On an American blog they thought it was cool we have some "tricked out BMW 5 series" police cars - seen here.
To be honest I've no idea where the blue/yellow check pattern comes from, I'm more used to seeing the old style orange/yellow. I agree the new yellow colour clashes badly with the blue, it needs to be not so bright and fluorescent IMO.
But yeah I also think this is a decent request. Nothing wrong with US police vehicles they just have an incredibly boring design. Practically any European police force would be good actually.