It is just… rain? I’m very confused if I’ll be honest. Your jacket gets wet, or you carry an umbrella so you stay dry? It rains 7-8 months of the year here, I genuinely never thought of it as a reason to drive so might be the wrong person to answer. As long as I’m not drenched (never happens unless i’m out for a rainy run on purpose), who cares the jacket will dry once I get in.
I've heard "some people use their 2 ton car as a rain jacket" and thought it was urbanist hyperbole, but here you are.