Hi Mate,

I'm pretty sure it's fitted OK - I checked and double checked it before bolting the tank back on. The resonating aspect did cross my mind - and I made a quick check to make sure that nothing was touching. I initially thought that one of the fittings could be touching the boot floor and making that vibrate but it doesn't look like it - it's quieter in the boot than it is underneath...

The pump is a Bosch 003. I was quite impressed how well it fitted - my old sender leaked which is why I had to take it all apart and replace the pump. Now the leak is fixed but it makes this awful noise.

I hate cars sometimes...

Cheers
Mark