Here is my first attempt at a modification, albeit its only minor.
I fumbled around and installed my first set of interior lights into a few passenger cars.

First the cars ...new.... and with shiny wheels, but no interior lights.




I had heard about a package that you could install with the LEDs to stop the them flickering as the carriage was moving, so I threw my hard earned on the counter at http://www.dccconcepts.com/ and collected a 6 pack to try out the system.
http://www.dccconcepts.com/index_files/DCCflickerfree.htm

Opened the pack and enough bits fell out to do a car..

LEDs, resistors, some springs to put on the axles for electrical pickup, a flicker free unit and some PCB board, in fact the package I bought had enough to light at least six cars.

Then, the dexterous bull elephant took the roof off to get inside.


This was a bit of a hassle because of these pipe looking bits on the end, that I'm sure are only there to stop people like me interfering with the original

But that is what crowbars are for...

Then came the welding, sawing and hacking to assemble the PCB board


I soldered 2 (or 1 and a half) PCBs together to make the board long enough for the 6 or so lights I will put on it for the car


This is a 4 LED wired into the board with a 1000 ohm resistor to dull the LEDS that I put in the first car I did

Depending on the strength of the light required, you can either use a 1000 ohm, 500 ohm or even no resistor in the process, and not knowing how bright the light would be I opted for a resistor
I then dropped the flicker free do-dad down into entry at the end of the car to hide it from view

This flicker free thing can keep the lights on for a couple of minutes after the power is off.
and ran the wires thru a hole in the floor for the pickups


and soldered the other two wires to the PCB board


I will hopefully finish tomorrow.


Jack

But I found the wheels on both side were isolated from the axle, hence no power flowing thru the axle to be picked up by the little springs supplied with the kit.