Well it looks more complicated than I was hoping but it hasn't stopped me.

I looked at the locking flasher relay but because it activates through the one terminal when locking and unlocking it wont work as I need 2 separate switched sourced

I've had to come up with a different approach if I wanted to still activate it off the central locking so I ordered a couple more components a spdt (single pole double throw) micro switch with 3 terminals (NO, NC, COM) with this I'm going to fabricate a set up under the door card so that it can be switched by the door pin that moves up and down this will give me my switched 12V in both directions being a double throw switch so one way (NO normally open) it will feed 12v to one of the self locking timer relay and then the other way (NC normally closed) it will feed 12V to the other self locking timer relay thus giving me what I need to move the spoiler in both directions.

The other item I had to buy was a DPDT (Double pole double throw) relay I need this because I'm unable to feed power up each wire to the spoiler with it still connected to the BCM so the dpdt relay will be switched via a switch 12v ignition feed so with the ignition off the spoiler circuit will be isolated from the BCM and the spoiler will only connected to my relay set up then once the ignition is switched on the dpdt relay switches and then re connects the BCM circuit and isolates it from my relay set up this has another benefit because the doors self lock when moving off this will switch the micro switch which in turn activates my timer relay but it wont be connected to the spoiler circuit so the spoiler will be unaffected.

Wired up like this will give me control of the spoiler both via the remote central locking with the ignition off and then with the ignition on I can then still use the interior dash switch and use the speed activation so best of both worlds I can also fit a concealed switch to deactivate the remote spoiler activation if wanted so it wont then move when locking and unlocking.

This all sounds complicated but really it isn't the only thing that might require some work is the fitting of the micro switch which until I get inside the door card is an unknown but I'm sure I can fabricate something easily.