What works for me is I snap on my toneau cover, make sure you point the hose away from the cockpit. In other words, make sure the water is going to the rear, front, or sides. soap it up, rinse the same way. What little water that gets in the cockpit is easily dotted up with a towel. Or if you are really nervous about water getting inside, fill up your cockpit with a bunch of "Shamwow's" That will surely take care of the problem. "It's made in Germany so you know it's good"
Washing and waxing the cobra is part of the fun. Enjoy
Chris