Bad radio reception while engine on

[New-to-commodore]

Hi
I just bought an Omega VE II 2012, and noticed the radio reception is not ideal, the further I go to west of Sydney, the worse it becomes, and almost dead when I go underground

However, today I have noticed that when I switch off the engine, and the key is not in, the reception is excellent, that is despite being underground, and once I put the key back and turn on acc (without starting the engine) the crack and woooosh returns back straight away

Any idea what is causing this?

Thanks

 

[MYVESSV8]

poor earth

 

[New-to-commodore]

Easy to fix?

poor earth

Thanks, easy to fix DIY?

 

[MYVESSV8]

multiple earths on the car, you may need to check all, easy diy