[KevinW]

Same as me - no weather gear, long journey to sva in a storm.
my suggestions if you suspect rain, based on bitter experience (although it was a laugh, but not at the time):

take out carpets beforehand if you can and stow in boot (I didnt),
take a full face bike helmet, as rain whipping in your face/eyes at 70mph is no joke,
take some towels/rags to mop out the worst,
take a mate to wipe the windscreen/instruments/dash at regular intervals on the way up,
take a complete change of clothes in a bin bag so you can be comfortable on the drive back.

And finally, take a full can of petrol so you dont run dry, (like I did when the fuel gauge jammed on half full!).

best of british...

Kevin