Yes , i run them through a 100AMP Solid State Relay (its a bit of overkill, but it this one i used) ....
http://search.jaycar.com.au/search?w...elay&view=list
The relay is controlled by a automatic pressure switch, and the pressure switch gets its power from a toggle switch on the centre console, then as a fail safe, the toggle switch only gets power when the IGN is turned to at least ACC position.
This makes it fully automatic once switched on, yet won't run without the key in the IGN (just in case you forget and leave the switch in the on position overnight) also the IGN key then becomes a emergency shut off.