North East Forum Moderator
The forums here for advice and knowledge, if you searched or asked about enough you would've got the info you needed to know that your A3 would need a wire installing and also found a guide which would've told you how to remove the ECU safefuly and properly - Not having a go, just stating that you could've saved yourself a bit of time and trouble.
You've snapped the retaining clips for the ECU, I'd just get some gaffa tape to make sure its secured on. If the ECU comes loose you'll run into all sorts of problems - loss of power steering, alarm going off, no trip computer etc etc.
Being an '04 I can bet my life that you don't have the wire.
If you were local I'd sort you out with the fitting of the wire and coding for £50 but I'm a bit of a trek for you.
Chances are the guy coded the cruise control fine, you just need the wire put in place to get it all working.