2016 Audi A1 1.4 TFSI Manual. Got a loud repetitive knocking/clunking coming from the passenger footwell area when the stop/start kicks in when stationary and in neutral. Goes away when the engine starts again. Booked it in for investigation at local Audi dealer - 3 week wait! Can't find any similar problems on any forums. Any ideas what it might be? What is still running whilst the engine has stopped? I can't get out and open the bonnet to have a closer look because undoing seat belt and/or opening door disables the stop/start. I'll probably disable it on the dashboard each journey until it's looked at.