Want to do something like that? Here's a DIY.
***Warning: I nor TN are liable if you mess up.***
First you're going to need:
1) LEDs (I would suggest buying the pre-wired LEDs. Chinese manufacturers sell them on eBay at 20 for 6 bucks)
2)
Quick Splice Connector with Male Disconnectors or any other connectors you may have around you.
3) Some wire.
It would probably be best to add a fuse to this setup.
Tools required:
1) Drill
2) Crimper
3) Super glue (may be substituted, just has to be able to hold the LEDs in place)
4) Screwdriver
5) Muscles
If you haven't messed around with your car yet, you will probably need:
1)
Insulated Crimp-On Pin Connectors OR
Wire Tap-In Squeeze Connectors
What I first did was removed the bezel, that black part underneath the shifter (you may need to put your car into D), and the cupholders.
If you have never played around with your car, you will need to find a power source. I believe in the S models you will not have this one connector. But this is how it looks like.

If you have this, crimp the
pin connectors to your wire and plug it in like this:
If you don't have the connector above, you will have to find the cigarette lighter and get your
squeeze connectors connected to your cigarette lighters.

Image stolen from Shft99's guide. :P
Now you have a power source! Crimp on the male connectors (the pink ones) of your
splice connectors onto the wire you have from your power source.
The next step is to take out your LEDs. Strip the wires on the end of them, maybe about 1/2 an inch. Separate the copper wires and then twist them up all together. Make sure that the red wire is with the red wires, and the black wires are with the black wires.
When this is done, your wires should be a really big bunch. Snap on the female end (the purple ones) of your
splice connectors.
Plug these in together, turn on your car and see if it works. If it doesn't retrace your steps and see how to fix it. When it does work, unplug the lights again, as you will need it for the next steps.
Take out your cupholders. You will now need a drill. If you bought 3mm LEDs, you will need a 2mm drill bit. (5mm LEDs? Use a 4mm drill bit) Why? You should manually widen up the holes with a screwdriver, just to make sure you have a snug fit.
This step depends on how many LEDs you want to put in your cupholders. I went with 6 (3 each) but you may go up to as many as you want.

As you can see with my install that I had a lot of excess wire left, so I just wrapped it around the cupholders itself a couple of times.
Put long piece of tape around the bottom of your cupholders. This will enable more of a straight line (unless you trust your eye). Mark the spots that you would like your LEDs to come out of.
Once you have finished drilling, widen up the holes with your screwdriver. Every now and then try to push your LEDs through the hole to see if it fits. If not, continue to widen up the holes. Make sure that once you're done the plastic little shavings on the other side will not block the lights.
When you're done with widening up the holes (and making sure your LEDs do fit), put a dab of super glue around each hole, then push your LEDs through the hole. Let it sit for a few minutes and it should be ready.
Plug in your lights (the male end into the female end), and put back your car. Tada! Illuminated cup holders.
Some may suggest getting a switch. In this case I would assume is that you cut your + wire and place a switch there.
If you were like me, I already had a LEDGLOW interior expandable lighting kit set. What I did was request a broken LED from them, strip off the wire, and got my power from the red and black wires.
When you splice the light's wire you will see 4 wires. Get electrical tape and wrap the blue and white wires (I touched those together on accident and now my lights are not working like before) Use the red wire as your + and your - wire as your ground/negative.