BMW radio and parking sensors problem[advice please].

I know we have so knowledgeable people on here.

My radio has stopped working 99% of the time and when this happens the rear parking sensors stop too.

The funny thing is when we went on holiday with the suitcases or have a heavy load in the back it comes back on
but only until the engine is turned off.
It seams the weight is pushing on something and connecting it.
I went in the back and press everything but couldn't get it to work.

Im taking it in Thursday so someone can have a look but it could be something simple as it does work
and is not completely broke.

Any help,TIA