Bought my 2008 Vogue a month ago and have been annoyed by the rubbish radio reception. It was so bad i used earpiece and my phone.

Read lots of forums most mention corrosion, there is some surface corrosion around the boot. Think it's more from carpet cleaning, wet dogs etc. No sign of any leaks current or historic. Considered the 5' piece of wire trick but thought I would try and find the problem first.

The FM aerial is in the heated rear screen so I removed the interior trim on the upper tailgate. Unbolted and cleaned up all the earths I could find - one each side near the hinges. Made no difference whatsoever.

The grey box (amplifier?) has 3 connectors , one is co-axial the other two are block (red and black). Removed the torks screw and dropped the box out. Could see very minor green corrosion on both the black and red connectors. Brushed it off the pins with a paintbrush. The box is a sealed unit so left alone. The torks screw looked like it could be an earth so I made sure it and the bodywork were shiny clean. Re-connected - no difference at all.

A week later I had another go. Removed the grey box and took it apart. The two halves are held together in the four corners. The upper half has a hole and it appears that a plastic pin attached to the lower half is melted into a mushroom shape thereby holding the two halves together. Attacked it with a 3mm drill and the two halves popped apart.

The board inside looked good with only two small areas of green mold.

Click image to enlarge

Im having the same problem so will give your plan a go.