LED strobe

I bought myself a pair of 6 bulb LED flashers. they have the wiring/switch/and speed control built into them and ready to go. I was wondering if anyone knew of a place i could tap into power in/under the dash. If so what would be the best way or the easiest ? this will be the final part of my install.
-thanks

additional info. I forgot to mention that it is a 1999. I expect there might be some differences in design.