Planning is everything. You don't get the pop up thunderstorms we did in Colorado. Forecasts would just say "monsoon thunderstorms after 2PM" and they would be somewhere, sometime around that time. I left shows when the storms were building up and inevitably would drive through a little bit of rain.
Like was mentioned, moving isn't such a problem unless you're taller than the top of the windshield. However, water did channel in around the doors and drip on the floor. Long lights would get wet so I always wore a hat.
I got caught in a hail storm once that really beat me up - my ears were bloody - and the passenger side had a couple of inches of hail on the seat and floor. Nothing a dustpan and towel and leaving it to dry in the sun couldn't take care of.
Driving a Cobra is like driving a Harley. I never knew any serious motorcycle rider that deliberately went out in a thunderstorm. Knew many that got caught and stopped under the bridge over the freeway
PS. If you have the snaps for one, a tonneau cover can help keep you and the passenger side dryer.