There is an aftermarket lip and it works pretty good. The oem design is worse in rain than snow, but the aftermarket lip pushes to the side where the channel is wider. https://www.amazon.com/dp/B07VBML8MW/ref=cm_sw_r_cp_apa_fabc_7B5S06AC12BBMJ4ZZX6C
Xipoo Fit Tesla Model 3 Spoiler Trunk Lip Rear Spoiler Lip Kit Waterproof Spoiler Wing Rear Windshield Wing for Tesla Model 3 (Black ABS) https://smile.amazon.com/dp/B07VBML8MW/ref=cm_sw_r_cp_api_glt_fabc_SX9Y4VVKSEYPRYYESMZY
Trunk lip spoiler.