12 volt to 3.5 volt! LED!

[Squshiee1]

Does anyone have any idea how to wire in line resistors with lights?
Here is the scenario i have 2 light casings for the front of my car and i want to fill them with these.... http://www.radioshack.com/product/in...odsInSession=1
but i am not sure how to bring them down to 3 to 4 volts.... i have seen these and they are very bright! Maybe someone has some 12 volt leds?

Thanks for the help.

[4Runninfun]

if you do an ebay or google search for 12v led lights you will come up with a slew of options.