Heavy rain problem

[Gramparrr]

Hi,
04 multistage forte. Very few problems but since mot and service l have on two occasions had a vibration/rattling, hard to describe but sounds as if the whole underside is falling off.  On both occasions it has been in very heavy rain, also windy.l at first thought it was the plastic under nearside wing which was loose so fixed it but again yesterday the noise came back.  No problem in dry weather and is not speed  related so l assume not caused by wind.  Anyone  experienced this?

[Zion]

Engine under tray missing? It is meant to be bolted to the lower ends of the arch liners. It holds them in place and needs to be there.

[Gramparrr]

Engine under tray missing? It is meant to be bolted to the lower ends of the arch liners. It holds them in place and needs to be there.

Thanks Zion,  I don't remember seeing a tray under the engine but will check.

[Zion]

It's worth a look. I had (have) no tray fitted and my other plastics made a din. I've tie wrapped them for now but they still vibrate. I bought a tray and fitting kit as the lower ends of the arch liners have nowhere to clip to without it, also the rear section behind the tray catches the wind.. unfortunately the weather here has been abysmal and cold so it can wait till better days.

[Gramparrr]

Drove down same section of m4 and no problems. Seems to be caused by heavy rain. Last time was worst l have ever experienced only few metres visibility but afraid to stop . Luckily 1/2 mile from slip road. Can't think what the water can be doing to cause so much noise or vibration