I just got myself an Ixon Sismic jacket to deal with this problem. It has a thermal and a waterproof liner too, so it's quite versatile. Used it with the liners out on the day I bought it and it was bliss. Used it with liners in on the LOFO ride, and it kept me dry, but we didn't get really bad rain, so I don't know how good the waterproof layer really is. My other Ixon jacket seems pretty waterproof so far (not that I put it to the test that much), so hopeful about this one too. I wouldn't yet go so far as to recommend the summer one, but so far, so good. Armour in the usual places. £90 at Megastore, Swindon (reduced).