Pay attention to LSPD police car it uses cscopcarla.dff/txd there are 2 models one is drivable and one is used in cutscene, it was not supposed to be Beta SFPD.
Error not SFPD https://cs3.gtaall.com/screenshots/4dc09/2015-11/large-fit/c13fba12ea3a6738355192a79ced8ce8f3b72098/306804-gta-sa-2015-11-22-21-27-01-69.jpg