The ELS does not manage the brightness of the lights, but only controls them, however, you have to download the visualsetting and import it either in your client or manage it in a server side resource
ELS Lights work on some cars, but not all, here for example:
This is how it should look like (according to the mods website)
But this is how it looks:
Only the lights work in the back. The lights are there and adressed in the XML file, with vMenu Trainer I can manually enable the front lightbar as an extra, but when using ELS to enable them, they just won’t turn on. This ELS vehicle works in singleplayer so I guess it must be something server side related.