Many different questions: Amplifiers ; Brake disc ; Warning sound

Hello, for now 10 months I am also the owner of a Ceed SW ED. So far everything is great, my last larger project was the installation of a Hifi system. But this was very tough: For the first time I had to overcome myself very much, because it was much easier with my last vehicle, I was also 10 years younger and no small daughter had to be supervised during the installation. There were questions like “what is an engine etc. still funny”. That’s how it is with little children. So the cables are all lying, even if I’m angry that I haven’t found a better connection for the remote than ignition + on the rear side of the radio (terminal A place 6). Now the first question: Where do I get to remote current that only gives signal when the radio is on? It works like this, but I would prefer to turn off the radio, too, and not only when I turn off the car. The rear right brake disc would have a blue ring and a red ring would have to be changed relatively quickly but the same axle. Now I tried to make myself smart because I’m dissatisfied in the workshop bitel lately with the high prices etc. but have found no statement that says must be changed urgently. Does anyone have any idea about this? And then another question: If I turn off the car and forget the light Unfortunately, he doesn’t complain, so no biep biep or something. Is that normal? I’d rather he would make a report before I do some stupid things in the morning. So hope the whole thing didn’t get too long, and someone would like to deal with my woes. Many greetings Manu PS: Probably it is handled just like in other forums, unfortunately the search for my questions did not fit exactly, however, at least similar problems were there but not Same.