As far as I'm aware as long as you don't turn on the ignition it's fine. I did the same process in my 8P A3 and I didn't get an error. I switched the ignition off and on several times in between disconnects to test the audio, then got lazy and left it disconnected and turned the ignition on and that's when the fault flagged up! D'OH!
I wouldn't take the chance mate. In work we do an electrical test which tests all the airbag connections, radio, interior lights, dash lights etc. basically any connection that will be a sod to get to later on. When we do it there is no engine in the car, no doors, wheels, seats etc. Just the dash, carpets, glass, wiper motors, roof liner, A B C pillars and trims, side airbags, ABS unit, electrics and all pipes etc. around where the engine will sit, battery in the boot and all body harnesses.
We get a simple lead with a crocodile clip on each end, one end we connect to the battery and the other to a metal stud or any metal on the car, even if the ignition barrel isn't in the car we can power up all the electrics. We then get a mobile PC which plugs into the car which we then run the electrical test...if it's green all is OK, if it's red we push a button to print out a piece of paper which tells us what the problem is. Airbag connections do come up! We plug them back in and test again...green this time
It's pretty weird the first time you see it all power up with just a lead off the battery...I would video it and post it but I may get into trouble as they don't like us taking picture let alone video lol!!
