The police interceptor from base GTA V.

Use https://gtaforums.com/topic/955449-iv-zolikapatch/ to unlock the 4 livery limit and make use of the +siren .ide flag

Vehicles.ide:
police3V, police3V, car, POLICE2, POLICE2, VEH@STD, NULL, 100, 999, 0.2348, 0.2348, 0.2,2, 1.0 ,1, ext_requi+ext_strong+livery+siren

txdp:
vehshareV, vehshare
vehshareV_hi, vehshareV

extra txdp for HQ interior:
police3V, vehshareV_hi
extra txdp for LQ interior:
police3V, vehshareV

carcols.dat (car3):
police3V, 133,133,133,