It seemed like the antenna itself was torqued down tightly. Pushing down gently on the antenna would produce water that was trapped underneath it. It wasn’t bad enough to cause visible staining or mold on the headliner, but it would smell musty after each rain. I solved that with some silicone...
I live in Houston so my experience is mostly with rain, though I have driven a GX470 in Colorado with KO2s and they are great in snow too. Honestly neither the KO2s nor the Nittos are great in rain, but the Nittos seemed to have less grip.
So I took my 2019 4runner through an auto car wash the other day, which was a mistake on multiple fronts. But afterwards the fm/am radio completely cut out (like there’s zero reception, not even static) but the xm is fine.
I pulled down the headliner and the shark fin antenna connections all...