12V Power for LED Array/Switch?

I'm installing 2 LED arrays in my car and am trying to have them controlled by a switch. Because I want to keep the look completely OEM, the only switch I could find is a momentary switch. I'm going to convert this switch in to a latching/locking switch using this circuit:

That's not my big concern. My concern is the power that I'm going to get. I'd like to get my power from a 12v accessory line. The LEDs+switch light will use around, but less than 1A. I plan on installing an inline fuse to protect against over-current.

Some people are telling me that I also have to worry about over-voltage. If tapping an accessory line, or maybe a fuse from the fuse box, do I have to worry about over-voltage that much? The LED arrays can take small spikes (a few volts) but I'm not sure how much more they can take. I'm really hoping to not need a voltage regulator because then there will be some voltage drop across the regulator and it'll just add to the circuits complexity (not an infinite amount of room behind the center console). These will be installed in a 2006 Audi S4.

Just for eye candy, here's the switch I'm using:

Here's the location where I'll put the switch, next to the passenger airbag light:

Here's what the LED arrays look like when operational: