What is the best car radio to install in my disco tdi 300?

Hello, I have the breaklights for my disco tdi 300 not working. I checked the bulbs and they are working. Where could the problem be?

Forward gears change up smoothly. I actually got another experience last evening when I packed at a hilly area. I could not move forward when I wanted to later. Even locking the diff could not help.

I have an automatic disco and it has a weak reverse gear. This is particularly so when trying to reverse on a hill or raised track. What could be the problem? Does it have anything to do with the gear box?