Can the siren/lights of the prisoner transport be disabled?

I am using ELS and ELS compatible vehicles in all slots, including the vehicle I use as a prisoner transport, which is the pstockade replaced with an LCPD Burrito. I assume that if it is possible to disable the siren, it would also disable the lights due to the nature of ELS AI vehicles, but I suppose that isn't too much of a problem. Is it possible, though? I've Googled it and searched and looked in configuration files for LCPDFR but found nothing. If it is not currently possible, could a mod make it possible? I suppose it's unlikely at this point anyone will be developing mods for GTA IV, but it's worth asking in case this is not possible otherwise, I suppose.