Got an aftermarket head unit in my EL and was wondering if there's a way to wire the head unit so that I can turn it on independently of the key being in the acc position.

Not really possible, sorry mate. What you're talking about is a feature built into factory headunits which allow you to use the radio/cd/cassette etc. up to 1 hour in the off position. EF/ELs had that feature too.
If you wanted something like that, you'd have to buy a headunit that incorporates that feature. I don't know if they exist in aftermarket decks though...
Or, if you want to be dodgy, you can wire the constant 12v and acc 12v together so the radio is constantly on. But that would drain your battery in no time, so you would add a switch onto the accesory wire which would act as the key in the accessory possition.
Place the switch somewhere discrete for a stock look and you should be fine.
That's if you wish to do that method...

u can run a switch or fun it constant power and turn it of at the head unit but it will kill your battery so probs just run a switch hidden so no ones knowes

Damn, thanks anyways guys.. Was hopin it was possible since its a fairly cool feature for when you want to duck into the shops and don't want to leave the keys with the passenger

Somewhat possible as TheELghia said. Won't kill your battery either as long as you're diligent with turning the cd player off. I've had mine wired into my EL this way for over a year now and haven't had it run the battery flat as I've made sure to turn it off when not in use. I'll take some happy snaps in the next few days for you.

as in turn the car off and take the keys out and leave the stereo on?

I have mine set up to do that until I open the door, as I used to sit in my car and listen to tunes and lock the keys in the car, so I wired it up like that.
I also have undervolt protection set up to cut the power if the battery go too low as I had amps etc.

My current ute is getting that, and also working to be able to turn the stereo on and off with my keyfob.

Let me know if you want a diagram for the stereo without the keys. It's very simple.

You could wire something up to do it..

A capacitor that powers a micro relay would do it.. the capacitor starts discharging when the acc is turned off.. but until the point that it's discharged, the stereo would run.

would have to experiment with the capacitor/relay size to get the right time period.

could probably also buy an electronic timing kit from Jaycar that would cut the relay off after a set time period.. not terribly difficult electronically speaking.

I had an interior light delay in my LJ torana many many years ago that I'd built using caps and a micro relay.

cheers

Frank

Thats a bloody good idea.

I don't have any other sort mate.