I don't know if 303 will streak from the rain or not, but here is a qoute from the AG website:
Application Tip: 303 recommends cleaning the convertible top twice using a brush before applying the protectant. The surface should be as clean as possible to allow the protectant to bond properly.
303 Aerospace Protectant is recommended by leading manufacturers of vinyl tops and accessories to keep their products in like-new condition. Absolutely nothing works better to beautify and protect vinyl.
"Dogs in cars again. Going away. Going away fast" - P.D. Eastman, Go, Dog. Go!