I used this Amazon cable gland and it's worked great so far. Survived some pretty heavy rains/snow here in the PNW over the last several months without any leaks
knock on wood https://www.amazon.com/gp/product/B00KV1PFS0/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&th=1
One thing I did differently than most folks I've seen is I used the existing factory holes instead of drilling new ones. I placed butyl tape underneath for additional waterproofing and used 3M VHB tape to attach the gland. Then I used so much Dicor sealant around everything. We'll see how it holds up but I really didn't want to drill another hole in the roof is why I went with the factory hole. It also worked out perfectly with our solar panel placement/orientation and able to run the wires down the back pillar to my electrical cabinet.
...