Yup it should be that way cause I'm assuming that the led strips have built in resistors. Just make sure to put in an in-line fuse so that if there is a short it will just blow the fuse. And to test the 12V source you can use a voltage meter or you can use something (can't remember the name) that has a light on top so that you know if there is current there or not. One thing to remember that some of those open slots only have power going to them when the car is on accesory or on completely or might be on all the time. The spot where I picked only has power to it when its on ac or completely on so that in case I forgot to switch the LEDs off I still wouldn't have a dead battery.
