I found this on Amazon that is used for motorcycles but it mounts easy on my 2016 Z521 windshield. Already tried it out and it definitely helps cut the wind on chilly runs. Its only $40 and clamps on without drilling. It should help with rain too?
64CC909F-42EC-4510-B759-D6E5FF8F0F72.jpeg
https://www.amazon.com/dp/B0813829LN/ref=cm_sw_em_r_mt_dp_U_mF2bEbS1YVWVN