britishgamer88 is a great source of uk car models over on gta5mods theres also some mods here on lspdfr
charges and such for compulite etc which helps
I dont think you can make lspdfr perfect as in terms of a uk setting but theres the odd thing about which kind of puts it in between the 2!
As dots says turn things down in lspdfr settings and pursuit menu that helps also.
So going back to your main question there isn't one thing/file that will do it just many hours of adding diffrent uk stuff into the game