I had a similar leak and thought it was the shower drain plumbing. I searched and searched to find the source of the leak. I don't know the layout of you MH, but my bathroom sink is next to the shower. I discovered that the water supply lines to the bathroom sink faucet were leaking. I replaced the faucet and converted to Sea-Tech fittings with shutoffs. Since then, I no longer have water in the wheel well.
2003 Dolphin L/X 6320