Problem solved !
You go in visualsettings.dat in update/update.rpf/common/data, then you need to find "emissive bits".
And there you change the values for the following lines :
- car.defaultlight.day.emissive.on "190"
- car.defaultlight.night.emissive.on "40"
- car.defaultlight.day.emissive.off "0.01"
- car.defaultlight.night.emissive.off "0.01"
and you get this :