[Heady]

What I noticed after work was that there were patches of condensation on the inside of the headlight enclosures - both sides.

I've only owned motorbikes for the last 12 years until I recently purchased the i30 - but I've never seen moisture in the headlight enclosure on my bikes.

I'm assuming that the headlight enclosures are water resistant and not air-tight. 
The weather here in the south of the UK has been reasonable for the last few days with temperatures of high 20's (degC) - that was until this afternoon when it rained and the temperature dropped to under 14degC.

Therefore, at some point the enclosures have been opened when it was hot and humid and now with the sudden drop in temperature the moisture in the air has condensed out. 
I'm assuming this only on the basis that I doubt a leak would occur in both enclosures at the same time.

However, any ideas on what I should do to remove the trapped moisture?  Any tricks of the trade?

[Dazzler]

Seems odd to me. I would leave your lights on next time you have a good drive to dry them out at least temporarily.

Hope your car hasn't been submerged in floods in a past life! 

[Phil №❶]

Headlight enclosures are not air tight. Possible air leak at the light fitting. Are the dust covers correctly positioned. On a dry day I'd remove the bulbs and expose them to sunlight for a few hours.

Pop the dust covers off and use warm air from a hair dryer for a few minutes to dry them out.

[eye30]

It is ok as i get it in mine and being up north to you we get lots and lots of rain.

As far as i can see the unit isn't leaking water in, it is moisture from the heat generated by the lights themselves when been on and cold or the humid atmosphere.

[Surferdude]

I've had it a couple of times. As has my daughter's Accent.
More like the misting you get inside the windscreen than any water droplets.
No deterioration of the reflectors even after 6 1/2 years on mine. Goes away pretty quickly if you turn the headlights on.

[Shambles]

It is ok as i get it in mine and being up north to you we get lots and lots of rain.

and also in the rear clusters, to a lesser degree.

Don't worry about it. If it's good enough for making a cup of tea, it's ok in the cluster

[Heady]

Thanks folks - that's interesting.

I would think that just heating the air inside the enclosure would not remove the moisture from the enclosure - just absorb it back into the trapped air within the enclosure. 
Then when the temperature drops again - it would condense out again.  Is my thinking correct?

I was considering using Desiccant Silica Bags in a stocking and insert into bulb location - leaving it for a night?  This should remove the trapped moisture (I hope)...
Amazon.co.uk: Desiccant Silica Bags

[eye30]

I was considering using Desiccant Silica Bags in a stocking and insert into bulb location - leaving it for a night?  This should remove the trapped moisture (I hope)...
Amazon.co.uk: Desiccant Silica Bags

In my opinion it will only return.

I was considering using Desiccant Silica Bags in a stocking and insert into bulb location - leaving it for a night?  This should remove the trapped moisture (I hope)...
Amazon.co.uk: Desiccant Silica Bags

You'll probably find that you already have silica bags inside the headlight housings, I have them inside mine.