Personally, I avoid getting my car wet like the plague. Then again, I have a choice. I would rather drive it -- than ride a motorcycle in the rain...
Sadly, because of previous neglect, mine still needs that 250 hours of rust-removal! However, I am pretty confident that most water will now stay out because I have replaced all the rubber seals and weatherstripping. And as mentioned, the drain hoses in the cowl vent must be in good shape, or water will come right in the floorboard area. That's what did me in. The trunk seal is also important -- its easy enough to check for water after a rain.