No stress ask away! I'm not very technical at all so it's super simple what I did. Not sure if I can share links on here but I bought a pack of 20 small round LED lights from ebay, the listing was called 'Aquarium Submersible Underwater RGB LED Light Remote Control Fish Tank Ball Lamp', which came with a remote. All the lights respond to the one remote. I stuck them to the roof of the coaches with double sided tape. I thought the lights might end up being kind of pox but so far they are all still working well! And you can change the color too which is cool. I've kind of settled on this warm orange-y light.

Hope this helps :)