go to "wicks" they have bright yellow reflective water proof trousers....
ok so they are made of plastic...
but they retail at @£10:00
and they are 100 % water proof..........!!!!!!!!!
and it may well keep the cold out..
and keep what your wearing normally on underneath...
so u can cut it to your leg size....
great in night time ride also........and shove under the seat when not in use.
actually i'm going to get a pair...