I have realized that on some mod cars the lights don't work, either rear or front or even both. Question: Can I try to fix that myself or is that too complicated (needed progs and skills!?) - thx for an answer of knöwing Jedi.
Assuming you have a key for acm (afaik it won't do it for the basic version) have a look under content/cars pick a car that has a problem and at the very bottom of the screen see if unpack data is there if not -(and you have paid for a key) go to settings-content manager and on the general page put a tick in the box for developer mode you may need to restart.