There is sometimes some confusion between the 'Auto Lights', 'Daytime Running Lights' and 'Coming Home Lights'. All three functions are different and are described as follows:

1. Auto Lights:

These require additional hardware and are only really available as a factory fitted option. It is possible to retrofit but the time and expense to do this isn't really justifiable. To see if you have this funtion, there are two key things to look out for:

i) Interior Switch

ii) Light Sensor or combined light and rain sensor

You can see if Auto lights are running by looking at the light switch. If the "A-OFF" symbol is lit up red, then this function is disabled and you will have to turn the stalk to bring on the side lights and dipped beam head lights.

To turn the autolights off whilst driving, you need to turn the lights on manually via the stalk before pressing the "A-OFF" button. Thanks to 'maddan' for this information.

With the light stalk switched to 'O' and the auto light function enabled, both the dipped beam head lights and side lights will come on when the ambient light level drops below a certain threshold. They will then automatically switch off above this threshold. Due to the position of the sensor, you may notice that the lights stay on more often in winter even if the light level is high enough not to warrant their use.

With the auto lights function enabled, operating the stalk will override it. Upon switching back to 'O' the function is enabled once more.

If you are unfortunate enough to need your windscreen replaced, ask the repairer to check the mounting frame for the light sensor. A batch of 'equal or approved' windscreens have been manufactured with this at an angle. It will not be possible to correctly seat the sensor if this is the case.

Auto lights are mainly found in Brabus Roadsters, particularly the Xclusive range, but not all. They are also present in the finale range and some 80bhp models (mainly imports). Retrofitting this function to a Roadster without it will involve replacement of the windscreen and a substantial amount of rework within the cabin. Depending on the model, it may also require replacement of the SAM. Hence, it is not really practical.

2. Daytime Running Lights

Many European countries insist that head lights must be on when driving, regardless of how bright it is. Smart have included an option to automatically turn on the headlights at start up. Turning the light stalk will have no effect on the head lights. If you did not own the car from new, you can check to see if you have them by trying to enable them.

If they do not enable, then you don't have the function pre-programmed into the SAM. It is unlikely that a dealer will be able to activate them.

3. Coming Home Lights

Again, this function is dependant on model and the pre-programming of the SAM. Coming home lights work by switching on the headlights for a short period of time when you unlock the car. It is a nice extra to have when approaching you car, especially if you have HID lamps.

All cars with Auto lights will come with this function by default. When the car is unlocked, the light sensor checks the ambient light level. If it is low, then it will switch on the headlights for around 5-10s or until the door is opened.

Again, if your car doesn't have it, it is unlikely that you will be able to get it added.