I replaced the factory unit in my 2007 A4 with a nice Sony Android Auto double-din unit. And whilst it appears to be wired correct (with regards to it's permanent and switched live), I have some issues with the unit rebooting when cranking the engine over. I think it's worse with the headlights on. The unit loses it's date and other weird stuff. I think the voltage is dropping too low when cranking.

Is this a known issue? Any common things to check?

I'm using a conversion kit.

Audi A4 Double Din Car CD Stereo Fitting Kit