Windows fogged. Wipers flailed uselessly. Top leaked. And that is my 1991 Elan.
I bought a new top in 1995 when I restored the 1971 Elan. Foolish me. It's still in the wrapping paper. 
My best sporty drive in the rain was 25 miles through an Arizona thunderstorm at 70 mph in an old Jag XK140. No point in slowing because we just have gotten wetter.
We dried out just fine - as did the Jag. 
Cazalea