I have a toggi perth coat. It's best for really cold weather, it isnt meant to be waterproof but mine's never leaked. It is bulky for riding in though.
Mine covers my rump! I love it. It is a Columbia, very good (and expensive) brand over here I am told, but it rarely gets worn because I just wear quilted coveralls and a couple of fleeces on top that get shed as I get warmer. I bought it from a Charity shop because I didn't have anything else at the time, still with tags, for $40 (about 20 pounds-ish) I also have Toggi bodywarmers and jackets that are excellent too, and, an absolutely ancient *whispers......candy stripe
* Puffa too that refuses to die even after 15 years of hard labour.