Well, there's a bit more to it. Simplified traffic cars also use a slightly lower-poly model with an insanely un-detailed interior, as for lights, if they're the same to MK2 Pessima lights but in lower quality, i'll just link those to the crosssport's simple traffic model.
Its only the interior thats lower poly, most simplified traffic have the same exterior and lower poly suspension and drivetrain. Also don’t forget to do the trim system properly. --- Post updated --- Also i hope you include the taxi