How Do I make car headlights shine in Poser? I want to parent lights to the car and have them moving and shining with car moving along. Cheers

Some cars have lights with a reflector, in the case, a point light correctly place, with a perfectly reflective material on the reflector could make it.
In other cases, you may also add two spotlights.

In any case, I suggest that you scale down the lights.

If it's the turn signal or taillights, points lights will suffice.
For the front light, and if you are using Superfly, you may use a blackbody node to control the  kind of light: the more kelvin, the more blueish the result.

Do the lights have their own material ? If so, can set to glow via super-ambient, dialled beyond 1.000. But, as I understand it, this route is deprecated in favour of setting 'emission' via Cycles. Also, 'super-ambient' seems to have a surface brightness limit. Cycles can be set bright enough to dazzle...

If 'lights' are a small or tiny portion of a mapped texture, you may need to set up a mask...

https://www.deviantart.com/nik-2213/art/Poser-glow-by-Super-Ambient-or-Cycles-Emission-909755263

NikKelly posted at 3:39 PM Sun, 11 June 2023 - #4467637

Do the lights have their own material ? If so, can set to glow via super-ambient, dialled beyond 1.000. But, as I understand it, this route is deprecated in favour of setting 'emission' via Cycles. Also, 'super-ambient' seems to have a surface brightness limit. Cycles can be set bright enough to dazzle...

If 'lights' are a small or tiny portion of a mapped texture, you may need to set up a mask...

https://www.deviantart.com/nik-2213/art/Poser-glow-by-Super-Ambient-or-Cycles-Emission-909755263

Are you referring to Super-ambient on the PoserSurface?  I see no such limitation, I can get the same dazzle as with the CyclesSurface node.  But it appears to me that the Emission node has built-in Inverse square that allows for light falloff with distance.  To overcome that you need to add a LightFalloff node especially if you want linear or constant light emission.

In terms of headlights, you need a light source with lightfalloff whether physically emitted or provided by an actual light.  But the OP has not elaborated if it's for firefly or superfly, and it would seem that the intent is to render an animation rather than a still image.

How about posting some renders of cars with the headlights on? I'd love to see what some of you Poser peeps come up with. Let's bring 'em on! 

Do not adjust your screen, this is a dark render.   I made the render large so you will discern something. Simply added emission to the glass part of the headlights. Just a test.

https://www.deviantart.com/nik-2213/art/Red-or-Blue-Red-Or-Blue-926923435

https://www.deviantart.com/nik-2213/art/DS-Kalea-7-Rogue-ported-to-Poser-as-FBX-Yay-951836762

https://www.deviantart.com/nik-2213/art/I-think-I-took-a-wrong-turn-955438718

Personally, if you want to recreate a scene as close to PBR as possible, you may need to address how your headlight shaders are designed.  If the vehicle has reflective components, glass, and mesh lighting to the headlight assembly, those will need to be changed.  The render below had a major overhaul of shaders using Vince Bagna Supershaders to convey a more realistic render.  I added a lightfalloff node to the mesh headlight bulbs for inverse square attenuation and headlight glass material to the glass portion.  Admittedly, I did use some denoising and bloom effect in PostFX.  

Many thanks everyone. Is it possible to post the settings for the headlights? Cheers

I just reread your OP and you are primarily interested in adding parented point lights to the headlamps.  It's not impossible to do but it depends on the car model and rigging.  If the model is created with its own headlamp assembly, i.e., mesh bulb, reflector, and glass/plastic covering, then you would want to apply an emission to the mesh bulb and a very shiny, metallic look to the reflectors.  The covering would require either a plastic or glass shader just for effect.  On the other hand, if the model is fashioned generically without many materials' shader zones, then you will need to add those zones with Poser's Grouping Tool.  This will involve additional work because individual body parts will need to be isolated and selected for conversion to a new Material Zone and,then, new shaders added.  In the render below, the 1936 convertible was very generically modelled, it had very few Materials Zones and no mesh headlamps.  Using the Grouping Tool, I created the headlamp covering (glass) and inserted resized point lights in each headlight, making certain that there were no light leaks and that they fit just right.  The image below is a Superfly render with a little post-work to clean it up.

As I mentioned before, everything depends on how the car was originally modeled and whether you need to make slight modifications to complete your scene.  Check your model and get back to us.