Having trouble seeing the brake lights in the broad daylight, running lights/turn lights? Try this suggested settings. You can adjust the level of brightness on each light to suit. 

Go in visualsettings.dat (update.rpf/common/data) and find these lines, then replace them:

# emissive bits
car.headlight.day.emissive.on			120
car.headlight.night.emissive.on			45
car.headlight.day.emissive.off		0
car.headlight.night.emissive.off	0
car.taillight.day.emissive.on			130
car.taillight.night.emissive.on			45
car.taillight.day.emissive.off		0
car.taillight.night.emissive.off	0
car.indicator.day.emissive.on			180
car.indicator.night.emissive.on			70
car.indicator.day.emissive.off		0
car.indicator.night.emissive.off	0
car.reversinglight.day.emissive.on		120
car.reversinglight.night.emissive.on	45
car.reversinglight.day.emissive.off		0
car.reversinglight.night.emissive.off	0
car.defaultlight.day.emissive.on		30
car.defaultlight.night.emissive.on		15
car.defaultlight.day.emissive.off	0
car.defaultlight.night.emissive.off	0
car.brakelight.day.emissive.on			160
car.brakelight.night.emissive.on		60
car.brakelight.day.emissive.off		0
car.brakelight.night.emissive.off	0
car.middlebrakelight.day.emissive.on	160
car.middlebrakelight.night.emissive.on	60
car.middlebrakelight.day.emissive.off	0
car.middlebrakelight.night.emissive.off	0
car.extralight.day.emissive.on			60
car.extralight.night.emissive.on		30
car.extralight.day.emissive.off		0
car.extralight.night.emissive.off	0
car.sirenlight.day.emissive.on			200
car.sirenlight.night.emissive.on		100
car.sirenlight.day.emissive.off		0
car.sirenlight.night.emissive.off	0
car.emissiveMultiplier	2
