Does anyone make one that is 100% waterproof and mounts to the bars and wires directly to the bike?
True motorcycle GPS's are made to be in the weather, vibration resistant and glove friendly (hence the inflated price tag they have). My Zumo 665 is waterproof and has a cradle that wires to the bike. It came with a handlebar mount, but if you needed something different, there are plenty of RAM mounts to choose from.
Better living through chemistry.